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MULTI POSITION 2-- STAGE GAS FURNACES

1. Figure 9 9MPV100 Lo HEAT CFM VS EXTERNAL STATIC PRESSURE 1800 1600 1400 1200 000 001 M 1000 D 011 100 809 101 0 800 111 400 200 0 LI LLL LLL LJ 0 1 0 2 0 3 0 5 0 7 1 ESP W C Figure 10 9MPV125 COOLING CFM VS EXTERNAL STATIC PRESSURE 2500 2000 000 001 1500 010 011 o 9 100 0 101 1000 0 111 500 0 0 1 0 3 0 5 0 7 1 ESP W C 440 08 2002 02 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 50 Two Stage Multi Position Furnace Service Manual Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Figure 11 9MPV125 Lo HEAT CFM VS EXTERNAL STATIC PRESSURE 2500 2000 000 1500 001 010 5 011 o 6 100 4 101 1000 9 110 111 500 0 0 1 0 2 0 5 0 7 ESP W C Figure 12 9MPV125 Hi HEAT CFM VS EXTERNAL STATIC PRESSURE 2500 2000 1500 000 001 01 0 i 011 100 1999 101 110 111 500 0 0 1 0 2 0 5 0 7 ESP W C ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 51 440 08 2002 02 Ser
2. K TT AUOLOV4 7 Ea OTG3M IHW 3ONVHO i amg 3000 03345 EN 3000 IVLSOWH3H L AOVLS L 4n aunssaud A1NO S1300N d STAGOW 3NOS HOLIOVdVO 980554 2 STAGE Hm 1234 SINGLE STAGE 1234 1234 1234 THERMOSTAT TYPE L E Ey NO 6 01 TUK HOLIMS LNOTION r Lova X 5vONCOSS anos MAWYOASNVYL MOLIOVdvO ASLT 0 8 MAX COMBINED HEAT ON DELAY H3AHOJSNVHI ASNA YS E 2 a gt SE z O 2 LL asm 1234 140 SEC ANO STAGOW 1 3 HOLIMS i 3unss3ud d1 S4YO LONGNOO 39409 971915 L10A IH HEAT OFF DELAY Um m 1234 1234 1234 100 SEC HOLIMS 4 Lo SVO HOLIMS ITE au RAIN Ho X90 TH3INI COOL ON DELAY 5 SEC COOL OFF DELAY 60 SEC NOLLO3NNOO 209 9 4 LOH LO3NNOOSIG 330339 i
3. DISCHARGE AIR Y Increase minimum from 8 to 18 for cold cli mates sustained temperatures below 0 25 23 33 15 VENT COMBUSTION AIR PIPING Vent and combustion air piping are an extremely important part of the total furnace installation Improperly installed or inadequately sized vent and or combustion air piping can be the source of many perceived furnace problems For example most problems associated with pressure switch operation can normally be traced to short comings in the vent and or combustion air piping Anytime these type Coupling ends of exhaust pipe Total pipe amp coupling same atmospheric zone F 13 Coupling on inside and outside of wall to restrain vent pipe DOWNFLOW See Vent Termination Shielding in Vent Section F 8 Min Ga 20 Max in same atmospheric zone Inlet Pipe Vent Pipes MUST be supported Horizontally and Vertically VENT PIPE atmospheric zone Increase minimum from 8 to 18 for cold climates sustained temperatures below 0 25 23 33a problems arise a thorough inspection of the vent and or combustion air piping should be conducted ALL MODELS require a v
4. Maintain 12 min clearance above highest anticipated snow level Max of 24 above roof Combustion Air Roof Boot Flashing Field E RS 9 O O 0 Support Field Supplied 45 Elbow L Field Supplied Air 25 22 i Combustion Ve Note Ld Support must be field installed to secure termination kit to structure 440 08 2002 02 16 Two Stage Multi Position Furnace Service Manual 18 EXHAUST BLOWER Always check the current Technical Support Manual for Exhaust Blower part nos Vent Fitting amp Clamps 90 Elbow Vent Pipe Side panel exit Vent Fitting amp Clamps DRAIN SIDE VIEW Rotate downward 20 to 30 19 CONDENSATE DRAIN TRAP This furnace removes both sensible and latent heat from the products of combustion Removal of the latent heat results in External Drain Trap condensation of the water vapor The condensate is re C moved from the furnace through the drains in the plastic tran Vent Pipe Vent Drain _ Side panel exit a sition and the vent fitting The drains connect to the external ly mounted condensate drain trap on the left or right side of the furnace Refer to Figure 26 Transition The condensate drain trap supplied with the furnace MUST Box Drain be used The drain line between the condensate drain trap and the drain location must
5. Combustion Blower Combustion Blower Mounting Screws 4 Pressure Switch Hose Transition amp 11 Section Vent Pipe PVC Pipe Grommet 5 g Hose n amp Clamps as Pipe Grommet Trap amp Gasket Condensate Rubber Coupling amp Clamps dwg 25 24 00b Horizontal Trap Connection 90 Street Elbow dow nwa rd 20 1030 Clamp ears Pointed OUT Preassemble and insert into furnace Horizontal Left Installations Dual Certified 9MPT amp 9MPV A2 Models See Figure 45 Note For easier installation of the drain hoses and clamps to the condensate trap follow the directions outlined below except do not make any clamp connections to any of the drain stubs and hoses until the hose routing and lengths have been determined Remove the condensate trap and drain hoses from the furnace and secure the drain hoses to the drain stubs on the trap with the hose clamps position the clamps as shown in Figure 45 Installthe condensate trap hose assembly to the furnace casing Hook one side of the clamp ears on the drain stub through the hole in the casing and push the condensate trap into position Secure with the two screws Reconnect the drain hoses to the stubs on the vent fitting and the plastic transition and secure with the clamps Relocate the plastic cap and clamp on
6. 42 TECHNICAL SERVICE DATA N9MPV 44 BLOWER PERFORMANCE DATA 9MPV 45 TECHNICAL SERVICE DATA 9MPT 52 BLOWER PERFORMANCE DATA 9MPT m tada CER t deals 53 WIRING DIAGRAM 9MPV ay iot Ups m FAC OU ORO s 54 WIRING DIAGRAM 9MPT 2 eder eee eR S ENDE OD ae eee ces 58 APPENDIX OF HELPFUL INFORMATION 60 Service Manual 1 INTRODUCTION This service manual is designed to be used in conjunction with the installation manual and or technical support manual provided with each furnace These furnaces represent the very latest in high efficiency gas furnace technology Consequently they incorporate the use of certain controls that contain highly sophisticated elec tronic components which are not user serviceable there fore it is essential that only competent qualified service personnel attempt to install service or maintain this prod uct This Service manual was written to assist the professional HVAC service technician to quickly and accurately diagnose and repair any malfunction of this product This service manual covers several different models in two 2 families of our new multi position furnaces Variable Speed D C Blower Motor models in the Condensing fur nace family and 2 speed P S C Blower Motor m
7. Rubber Couplin amp Clams 2 Section PVC Pipe Plastic Optional Cap Vent Fitting amp Clamps Plastic Caps _ 5 8 Hose amp Clamps el Combustion Blower Combustion Blowel Mounting Screws 4 Pressure Switch 7 Transition 90 Street Vent Pipe Grommet Air Intake Coupling Some Models Plastic Cap have one pressure switch 3 H 90 Street Condensate Trap dwg 25 23 55bs Pressure Switch Pressure Switch Horizontal Trap Connection Blower Hose Blower ose amp Clamps Transition Box Clamp ears Pointed OUT Pressure Switch Drain Hose Transition Line Preassemble and insert into furnace Horizontal Right Installations Dual Certified 9MPT amp 9MPV See Figure 46 Note For easier installation of the drain hoses and clamps to the condensate trap follow the directions outlined below except do not make any clamp connections to any of the drain stubs and hoses until the hose routing and lengths have been determined Remove the condensate trap and drain hoses from the furnace and secure the drain hoses to the drain stubs on the trap with the hose clamps position the clamps as shown in Figure 46 Install the condensate trap hose assembly to the furnace casing Hook
8. 12 34 SETTING ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 56 THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 440 08 2002 02 Service Manual Diagram 1 HP DC Blower Motor 9MPV075 100 amp 125 A2 Two Stage Multi Position Furnace Wirin a GLECLOL Saaads ONILVINOUID 8 SNILV3H S3HOLIMS ONI LSNT OY 303 STVONVIW 335 9 80L A MV 38 15 d PAXOLOWS J9VL 10A SW 44141044 7777 LINDYID SOVLIOA OV 1 IHL HOLIMS ISAW SV IH IM IVNIOIHO JHL JO qaivog LINOHI9 IVNYALNI NadO SAIS HLOS NO SISSVHO qald SOVLIOA 2 O 91 51 O TIM Std3 13W LIOA LSOW 3LON AYOLOVA 39VLIOA p p 07813 AHOLOV4 39VLIOA 2 STAGE THERMOSTAT TYPE SINGLE STAGE ELE 1234 1234 1234 30 SEC 1 3euns JOHINOO nsd 852 YOLOW OG 10 1OH4 LNOO Lv LSIGINNH 47 YOLOW MO1 HEAT ON DELAY NO HOLIMS STSGON d7 HOLIMS TON 22 1 guns Sad asnavs wz woo I
9. NO 54445 NI OL HOLIMS LNOTION H3WHOJSNVHL EAC HUM 0 8 A MAX COMBINED NI TL 79053577 i3 NHOJSNVM LI E 2 Q gt 2 O gt lt LL anm 1234 140 SEC x SIFON d HOLIMS 1 Sed SYOLONGNOD 434409 91315 LTOA HEAT OFF DELAY 100 SEC m F EH 1234 1234 3HnSS3Hd qunssaud MO1 d HOLIMS HOLIMS 7 C t HAON NO J OL HOLIMS LNOTION COOL ON DELAY 5 SEC COOL OFF DELAY 60 SEC NOILO3NNOO qui ONIOIAH3S 30438 LO9NNOOSIO INVHOVIG NOLLO3NNOO Umm 1234 SETTING l 440 08 2002 02 57 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL Two Stage Multi Position Furnace oMPT A1 Diagram Service Manual Wirin O9EELOL Saaads ONILVINOUIO 8 SNILV3H HOS 541 03345 ONI LSNf GV SIVNNVW 335 LINOHIO TVNHSINI IN3 IVAInO3 SLI 9 901 Ad 2 1VLSON43HL Q3OV 1d3 38 LSNW 38 LSNW OLNI eV MOT SE JOVIS M 3LIHM AHL 5 SV TIVNIOIHO JHL
10. Feet of pipe is whichever pipe run is the longest either inlet or outlet side Standard Termination Rooftop Termination Inlet is optional on Dual Certified models 25 o S 4 12 Above roof snow accumulation level B 8 Min 20 Maximum except in areas with extreme cold temperatures sustained below 0 the 18 Min 440 08 2002 02 Two Stage Multi Position Furnace Consult the appropriate Venting tables and or piping chart for the model series you are servicing Sidewall Termination 12 or More Above Snow Level or Grade Level 18 Minimum for cold climates substained below 0 F gt 3 2 Inlet is optional E Dual Certified models 2 LE Ta 25 00 05F GRADE LEV L Concentric Vent and Combustion Air Roof Termination 12 Min Grade or Snow Level Combustion ir Dimension A is touching or 2 maximum separation Concentric Vent and Combustion Figure 18 Sidewall Termination Vent 25 22 02d Dimension A is touching or 2 maximum separation Two Stage Multi Position Furnace Service Manual Sidewall Inlet Vent and Exhaust Recommended Alternate Installa Air Termination tion for Sustained Cold Weather 0 F amp below OVERHANG 12 MIN EXHAUST 8 Min 20 Max 18 Min for Cold Climates 6 Sustained Below 0 F Ne ee 12 Min Grade 12 MIN Ground Level Or Snow Level OR Snow Level
11. NOILOANNOO MOOHS T1VOIHIO313 439ONVAO SETTING ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 58 THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 440 08 2002 02 V 09EEL0L ONILV1NOHIO 8 ONILV3H H3dOd SdVv L 03345 STVANVW 33S _ didana ANOLOVd3OVLTOA GaldiLoau SOVL IOA ISIN A MOTISA 9NRIM UNOHO IVNHSINI OV NI HOLIMS AENEAN SAL LIA dS CLR INEO SLO ANY a M 3UHM 39VLIOA N3dO 3015 HLOS NO SISSVHO pc 1 39VITOA OLSLIOA 91 51 TIM 1 LSOW O 41315 2 LON 9 39V L10A NMOMH OTda IHW 3ONVHO LVLSOWYSHL ania O1WN 3n1a IH HOvY19 D 5 L 4 3915 1VISOWMSHL LH ovi 3409 HG 1 3309 40109 HOLIMS KINO 5 S133OW 3WOS Service Manual 2 STAGE SINGLE STAGE 1234 1234 1234 FAN CONTROL MODULE 51 1234 180 SEC 1 anm 1234 140 SEC HO1IMS HOLIOVdVO THERMOSTAT TYPE LVLSOWYSHL g HOLIOVdvO 15 NIV p 108845 NO Ap
12. 010 600 011 100 29 101 110 111 400 200 0 0 1 0 2 0 5 0 7 1 ESP W C 440 08 2002 02 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 46 Service Manual Two Stage Multi Position Furnace Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Figure 3 9MPVO050 Lo HEAT CFM VS EXTERNAL STATIC PRESSURE 1000 900 800 700 0 s 0 001 5 010 011 500 5 100 9101 400 110 111 300 200 100 0 0 1 0 2 0 5 0 7 ESP W C Figure 4 9MPV075 COOLING CFM VS EXTERNAL STATIC PRESSURE 1800 1600 1400 1200 8 000 001 O 1000 010 1 100 800 101 0 600 111 400 200 0 0 1 0 3 0 5 0 7 1 ESP W C ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 47 440 08 2002 02 Service Manual Two Stage Multi Position Furnace Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Figure 5 9MPVO075 Hi HEAT CFM VS EXTERNAL STATIC PRESSURE 1400 1200 1000 000 gt 800 00
13. conds it takes the smallest normally 1 cfh dial on the aural Gos No oi Seconds Time Per Cubic BTU Per gas meter to make one complete revolution BTU Content Per Hour in Seconds Hour 4 Calculate HIGH fire input rate by using ACTUAL BTU 1000 75000 content of gas in formula shown in example 440 08 2002 02 Two Stage Multi Position Furnace 7 L P PRESSURE SWITCH Models converted to operate on L P Gas will be installed with an L P Pressure Switch The switch will belocated inthe gas supply line in a Tee fitting just ahead ofthe gas valve The purpose ofthis switch is to preventfurnace operating un der low line Supply pressure conditions Operating under low line pressure conditions can create problems such as in complete combustion flashback sooting etc The switch is a Normally Open pressure operated switch that is wired in series with the furnace Lo fire pressure switch The L P Pressure Switch closes when line Supply pressure is 8 0 W C or higher the L P Pressure Switch Opens if line pressure falls below 6 0 0 6 W C interrupt ing power to the gas valve It is located electrically between the Main Limit Switch and the furnace vent pressure switch The switcht is located electrically between the Furnace Lo fire pressure switch and the gas Valve 8 HIGH ALTITUDE OPERATION Thesefurnaces are designed to operate in the majority of the country without modificati
14. U Unit Identification 2 V Vent Termination Concentric 16 Vent Termination Standard 14 Vent Combustion Air Piping 14 Wiring Diagram 54 59 Wiring Control 10
15. 1093 CFM Service Manual NOTE This same method can be used on models equipped with a P S C motor to determine the COOLING airflow by TEMPORARILY connecting the cooling speed tap wire to the HEAT terminal of the FAN Control NEVER connect two 2 speed tap wires to the same terminal Do ing so will cause motor failure VARIABLE SPEED MODELS D C MOTOR The heating cooling and circulating blower speeds can be adjusted by changing the switch settings that are located on the side of the blower motor see Figure 36 Switches 1 and 2 adjust the circulating blower speed Switches 3 4 and 5 adjust the heating speeds Switches 6 7 and 8 adjust the cooling speed See the Technical Service Data Sheet for the model you are servicing to obtain the switch settings for the desired airflow rates CHANGING BLOWER SPEEDS The procedure for changing blower speeds if needed dif fers based on whether the unit is a variable speed model or a2 speed model See Figure 36 and Figure 38 and the appropriate sections for the model you are servicing VV Zi Lu Electrical shock hazard Turn OFF power to furnace before changing blower speeds Failure to do so can result in personal injury and or death VARIABLE SPEED MODELS D C MOTOR The heating cooling and circulating blower speeds can be adjusted by changing the switch settings that are located on the side of the blower motor see Figure 36 Switches 1 and Z2
16. 3 Observe temperature at which switch opens burner operation ceases 4 Remove blockage from return grille s 5 Observe temperature at which switch closes burner operation resumes 6 Compare readings with the limit setting listed in the appropriate chart for the model you are servicing If switch is opening within the specified range then it is sim ply doing its job and the cause ofthe over temperature must be determined and corrected 11 Service Manual If however the switch is found to be opening prematurely then it should be replaced When replacing ANY limit switch use ONLY a switch of EXACTLY the same temperature set ting Use of a different temperature limit switch can create a dangerous situation Some of the main limit switches used in this series are SIMILAR IN APPEARANCE DIFFERENT TEMPERATURE SETTINGS HOWEVER ARE USED for different models Be certain you have the correct control for the model you are servicing ROLL OUT LIMITS Those Normally Closed unit switches wired in series with the Main Limit switch on the top are mounted on the bottom left amp right of the burner box The switches are manual reset type When replacing this Switch be absolutely certain the correct one is used Figure 12 Typical Roll Out Limit Switch CAUTION NEVER use an automatic reset roll out switch to replace a manual reset type roll out switch Doing so may cause potentially unsafe and or intermit
17. bustion blower inducer OFF At end of the 5 minute delay another cycle begins 41 Ignition system control switch must be in the ON position Pressure switches operation tubing and wiring Restrictions in furnace air intake or vent piping High winds blowing against vent Main limit switch Limit and rollout switch wiring is in good condition and se curely connected Restriction in duct work Dirty filter Dead blower Blocked duct work Pressure switches stuck closed system will wait for pres sure switch to open Pressure switch miswired or jumpered Ignition system control switch must be in the ON position Pressure switch operation tubing and wiring Restrictions in furnace air intake or vent piping 440 08 2002 02 Service Manual Two Stage Multi Position Furnace SV9541G ELECTRICAL VARIATION 2 STAGE Connector Pin Voltage Signal When Signal is Present Neutrals Neutral 0 VAC Always present 5 1 4 QC s Neutral and earth ground should be at the same potential 120 VAC Line Line Voltage 115 VAC Present when blower door interlock switch is closed XFMR DC MTR 3 1 4 HEAT LOW Fan power 115 VAC Present when Low Heat fan speed is on G request 4 Low Heat W1 mode after Heat Fan On Delay Heat Fan Off Delay HEAT HIGH Fan power 115 VAC Present when High Heat fan speed is on High Heat 1 4 W1 amp W2 mode Open Limit mode COOL Fan power 115 VAC Present
18. 25 23 73 Dimension A is touching or 2 maximum separation Sidewall Inlet Vent and Exhaust Air FRONT VIEW SIDE VIEW Termination with Exterior Risers 18 Min for Cold Climates 8 CL Sustained Below 0 8 Min wi 20 Max Exhaust 12 Min 2 gt Grade or M Inlet Snow Level Li Same Joist Space 18 Min for Cold Climates Sustained Below 0 F Min As 12 Min Grade or Snow Level 440 08 2002 02 15 Service Manual Two Stage Multi Position Furnace 17 CONCENTRIC VENT TERMINATION Concentric Termination Kit NAHA001CV Attachment Table 6 amp NAHA002VC Venting Table Dual Piping ONLY 3 x 2 Bushings or Strap 3 x2 Bushings Field Supplied Combustion 50 000 amp 75 000 Btuh Furnaces If 3 vent not used air NAHA002CV 35 amp 4 90 elbows with 2 PVC pipe Field supplied 100 000 amp 125 000 Btuh Furnace NAHA001CV 35 8 4 90 elbows with 3 PVC pipe 1 Do not include the field supplied 45 elbow in the total elbow count 2 If more than four elbows are required reduce the length of both the inlet and the exhaust pipes five feet for each 45 Elbow additional elbow used Note Field Supplied 3 Elbows are DWV long radius type for 2 and 3 vents Securing strap must be field installed to prevent movement of termina tion kit in side wall 25 22 02
19. 60 000 Btuh and a desired temperature rise of 50 F range of 35 65 F allowable and a measured external static pressure of 0 2 W C while operating on medium low speed with a dry coil 60 000 60 000 50 X 1 08 59 4 1010 Checking the blower performance data for this model see Table 7 indicates that 0 2 W C E S P medium low speed delivers 1030 CFM Accordingly medium low speed is the proper speed to be used in this example for the HEATING speed COOLING A blower speed must be selected that will provide proper air flow Nominal 400 CFM per ton for the size capacity air conditioning coil being used at the external static pres sure of the Duct system installation This requires CHECKING THE EXTERNAL STATIC PRESSURE and then consulting the BLOWER PERFORMANCE DATA to determine the required speed tap EXAMPLE A 24 000 BTU 2 ton air conditioning system using the same 75 000 BTU furnace as in the previous ex ample The external static pressure is measured with the unit operating on Low speed and found to be 0 4 W C with a wet coil 400 CFM nominal per ton required 400 X 2 800 CFM required Checking the blower performance data see Table 7 for this model indicates that 0 4 W C ESP low speed is delivering 735 CFM Accordingly low speed is the proper speed to be used in this example for the COOLING speed 440 08 2002 02 Service Manual Blower Performance Data 75 000 Us BTUH PSC Moto
20. Any combination of 5 abnormal events during a single call for heat will result soft lockout An abnormal event is a Flame Sense Failure During Run Airflow Proving Circuit Open During Run or Limit Circuit Open During Run The flash code will indicate which was the last abnormal event that put the system into the soft lockout state based on the table above 440 08 2002 02 21 Service Manual 24 CHECKING FLAME CURRENT The Honeywell SV9541Q Ignition system used in this furnace series proves verifies flame via the Flame Rectification method Flame Rectification is a process of converting Alternating Current A C into Direct Current D C During the ignition sequence an alternating current A C Voltage is applied to the Flame probe When the burner lights the flame conducts an electrical cur rent between the flame probe and the burner ground Due to 25 CAPACITORS Figures Checking Capacitor AN Microfarads 5 uf 100 uf 1000 uf 26 BLOWER ASSEMBLY All variable Speed models use one of two different variable speed D C motor direct drive blower assemblies Dif ferent size HP motors and or different diameter blower wheels are used in the different models to obtain the re quired air flow All 2 Speed models use a multi speed permanent split ca pacitor motor direct drive blower assembly Different size HP motors and or different diameter blower wheels are used in each
21. Cooling CFM 0 50 Static Furnace Model 0 Do Ls 3 o Toe Factory setting Approximate air temperature change from factory setting 0 20 static on high heat ft 1 fo 621 650 830 986 556 543 750 800 Factory setting CONTINUOUS HEATING COOLING CFM SELECT CFM SELECT CFM SELECT 010 EXAMPLE Cooling Airflows Switches 6 7 8 8 INPUT 000 3 5 Ton SIGNAL OR 001 3 0 Ton THERMOSTAT 010 2 5 Ton DIP CONNECTIONS 011 2 0 Ton SWITCHES ndi See Technical Support Manual for correct airflow ix ER AE 1272 rates SPLIT CAPACITOR MOTOR ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 440 08 2002 02 45 Service Manual Two Stage Multi Position Furnace Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Figure 9MPV050 COOLING CFM VS EXTERNAL STATIC PRESSURE 1400 1200 1000 000 001 800 010 5 011 100 600 101 3 110 2 111 400 200 0 0 1 0 3 0 5 0 7 1 ESP W C Figure 2 9MPVO5O Hi HEAT CFM VS EXTERNAL STATIC PRESSURE 1200 1000 800 000 5 001 o
22. SOVLIOA lVISOWMHSHL 9 39VIS d TIONIS s 2 STAGE 40109 THERMOSTAT TYPE SINGLE STAGE rete gouns 9 18 616 1V1SONMHSHI aamo 192192 mz ao Ovis HOLIMS 3NOS 1 HOLIMS 93 MO1 5 iu 2 o lt I IN t N t N t IN t N HUM 0 8 MAX COMBINED NO lt 31535 Ave NI OL HOLIMS LNOTION 180 SEC U3WNd4O4SNV4 L Arc YAWYOASNVYL FAN CONTROL MODULE 51 gt EN ANO S14CON d7 HOLIMS 140 SEC SYOLONGNOD HHddO9 AUT 91914 LTOA IH ies HOLIMS 4 gunssaud saan MO1 HOLIMS s aouns HOLIMS MOOTYALNI 7 100 SEC HEAT OFF DELAY zs 1234 1234 o EJ xod 1 NOILO3NNOO qii ONIOIAH3S 340438 LOANNOOSIG INVHOVIO COOL DELAY 5 SEC COOL OFF DELAY 60 SEC
23. SPOND DIFFERENTLY to certain control wiring practices which have been generally accepted in the HVAC industry for many years For Example For years installers have run a wire from the Y terminal of the room thermostat and connected it di rectly to the contactor coil of a condensing unit not mak ing any connection to the furnace with this wire Then run the low voltage Common wire from the condensing unit back to the C terminal of the furnace With the HONEYWELL ST9162A electronic Fan Timer Furnace Control used in the models of this series howev er the Y terminal of the furnace does in fact serve a par ticular purpose Failure to connect it will result in certain improper operation as follows The COOLING fan speed is energized via the Y terminal Failure to connect the thermostat terminal to the Y terminal on the control will result in the failure to energize the COOLING speed on a call for cooling from the thermo stat Depending upon the model either the LOW HEAT ING speed or the CIRCULATING speed will be energized instead via the terminal For more detailed information about this control see the section on the ST9162A control beginning on page 23 of this manual fore the furnace can resume proper operation A WARNING Fire hazard Limit controls are factory preset and MUST NOT be adjusted Use ONLY manufacturer s authorized replacement parts Failure to do so can result in deat
24. will need to be changed Refer to Changing Blower Speeds on the pages that fol low for the proper procedure Select the speed tap or dip switch setting that ap pears to most closely provide the required air flow for the system Recheck the external static pressure with the new speed tap External static pressure and actual air flow will both have changed either higher or lower depending upon speed tap selected Recheck the ac tual airflow at this new static pressure to confirm speed tap selection 2 10 11 Repeat steps 9 and 10 if necessary until proper Speed Tap and airflow has been obtained Two Stage Multi Position Furnace p Checking Temperature Rise Thermometer Thermometer Supply Air Temp 3 min from ra diant scene CHECKING APPROXIMATE AIR FLOW If an inclined manometer or Magnehelic gauge IS NOT available to check the External Static Pressure OR the blower performance data is unavailable for your furnace approximate air flow can be calculated by Measuring the temperature rise then using the following criteria The approximate CFM actually being delivered can be cal culated if the OUTPUT Btu of the furnace is known by op erating the system in HEATING and using the following formula Output BTU Temp Rise x 1 08 CFM EXAMPLE Using a 75 Mbtu Input furnace with an OUT PUT of 59 000 Btuh and a measured temperature rise of 50 59 000 or 59 000 50 x 1 08 54
25. 50 Mbtu amp 75 Mbtu 100 Mbtu 125 Mbtu Long 40 Ft 5 90 Elbows Always check current Technical Support Manual for updated information Lower Lesser Negative Pressures Lower than normal negative pressures measured at the Combustion Blower may be caused by 1 Long 40 Ft 5 90 Elbows Long 40 Ft 5 90 Elbows Restriction on the Outlet side of the combustion blow er I E Blocked Flue Vent too long Heat Exchanger leak etc Short 5 Ft No Elbows 1 80 2 60 Short 5 Ft No Elbows 1 80 2 60 Short 5 Ft No Elbows 1 80 2 60 Low Fire 1 20 1 90 1 00 1 80 1 20 1 90 1 00 1 80 1 30 2 30 1 70 2 50 1 20 2 20 2 Leak lack of restriction on the Inlet side of the com bustion blower Higher Greater Negative Pressures Higher than normal negative pressures measured at the Combustion Blower may be caused by 1 1 30 2 30 1 70 2 50 Restriction on the Inlet side of the combustion blower LE Plugged Heat Exchanger air inlet orifice too small Typical Vent Combustion Air Piping Installation UPFLOW 8 Min 20 Max in same atmospheric zone Aluminum or non rusting shield recommended See Vent Termination Shielding for dimensions Inlet Pipe de structure 8 outsi Min p Vent Pipes MUST be supported Horizontally and Vertically
26. Connect a section of the 5 8 OD hose with a funnel to the drain stub and pour eight 8 ounces of wa ter into the trap Remove the hose and replace the plastic cap and clamp This will prime both the vent and the transition sides of the trap The startup of a furnace will have milky or oily looking con densate coming from the furnace This is residual drawing lube in the secondary heat exchanger that is being washed out by the condensate The condensate will clear up as the 27 Service Manual connection to the control Their purpose is to provide a place to connect or PARK any UNUSED speed tap wires P S C motors ONLY to keep them out of the way and prevent them from shorting out against the furnace casing or each other Figure 38 Honeywell ST9162 M1 amp M2 Terminals Cooling Terminal Heating Terminals Dip Switch Y2 Terminal 25 22 44 furnace operates Poisonous carbon monoxide gas hazard The use ofaventtee atthe outlet ofthe condensate trap is required if the condensate line from the trap to the open drain is properly sloped 4 per foot downward slope Do not trap the drain line in any other location than atthe conden sate trap The combustion blowers and blower gaskets are different on some of the furnace models There are two part numbers of the combustion blower for the 2 stage furnace models See the Tech Manual for the cor
27. L65 HOLIMS L 6 4 aunss tdd MO1 HOLIMS L MOO TH3LENI NO NI OL b H21IMS INOTION SNIOIAMH3S 330338 LO3NNOOSIG QHVZVH MOOHS TVOI410113 LV LSOWHaHL 10 1VISIGIINnH lVISOWMH3H L Asi vaNoo3S NHOJSNVH L ASH Q 3snd vs 1 M3ddOO 110A IH HOLIMS MOOTYALNI NOLLOANNOO 91913 INVHOVIGO NOILOANNOO 440 08 2002 02 55 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL Two Stage Multi Position Furnace HP DC Blower Motor 9MPV050 A2 iagram D Service Manual Wirin 8 L9 L0L saaads ONILVINOUIO 8 SNILV3H YO4 S3HOLIMS ONILSNPAV STVONVW 33S YO OcS0L NMV Q39V 1d3 LSNW LI C39 V Td3 AYOLOVA J9VLIOA LSNW 39NVllddv JHL lt SV TVNIOTHO AHL MOTIAA LINDYIO TWNYSLNI 93134934 JHL HOLIMS 330SS38d YO IWLSOWYSHL 91915 N3dO NV 30 53015 SISSVHO SLIOA 1 39 18 AYOLOVA 9L L QV3M SSH3 L3AW LIOA LSOW 31ON
28. OFF DELAY CHECKING COOLING FUNCTIONS 1 JUMPER amp TO 2 CHECK COOLING FAN DELAY ON 3 CHECK COOLING SPEED FAN OPERATION 4 REMOVE JUMPER 5 CHECK COOLING FAN OFF DELAY 22 HONEYWELL SV95410 2 STAGE GAS VALVE IGNITION CONTROL Figure a0 Honeywell ST9541Q Ignition System Ignition Sensor Pilot Burner Sensor Manifold Pressure Adjustment Gas Valve Ignition Control The system consists basically of only two 2 components The Ignition System Control and the Pilot Hardware They operate on Two 2 power circuits received from the ST9162A Fan Timer Furnace Control One is the 24 volt power supply for the ignitor and to activate the ignition se 19 quence The second is a 115 volt circuit used to power the combustion blower The SV9541Q system is not polarity sensitive The SV9541Q Ignition System Control working in conjunc tion with the ST9162A fan timer manages the Ignition Se quence and the flow of gas to the pilot and main burners It is in essence a combination Gas Valve and Ignition con trol It contains sophisticated electronic components internally and has NO USER SERVICEABLE COMPONENTS Should a problem be verified internally within the device IT IS NOT FIELD REPAIRABLE and must be replaced The Pilot Hardware includes the pilot burner the hot sur face element that lights the pilot burner the flame rod that senses pilot flame
29. Service Manual Two Stage Multi Position Furnace TECHNICAL SERVICE DATA 9MPV A1 amp A2 Specifications 9MPV050F12A 9MPV075F12A 9MPV100J20A 9MPV125L20A General Gas Type L P L P L P L P Transformer Size VA 40 T stat Heat Anticipator 10 Input Btuh Std Alt Hi Fire Lo Fire 100 000 125 000 Output Std Alt Fire 70 000 87 500 Lo Fire 92 000 115 000 Temp Rise F Hi Fire 64 400 80 500 Lo Fire 40 70 40 70 40 70 40 70 Electrical Volts Hz FLA 115 60 9 8 115 60 8 9 115 60 9 0 115 60 11 2 Gas amp Ignition Gas Type Std Main Orifices No Size Gas Valve Honeywell Regulation Type Manifold Press Hi Fire WC Lo Fire WC Pilot Orifice Size Ignition Type Series Combustion Flue Outlet Size Inches Std Outlet Temp F Comb Blower MFD Volts Blower Transition Box Hi Fire Std Pressures of WC 5 No Elbows 1 80 2 60 1 80 2 60 1 80 2 60 1 80 2 60 40 5 90 DWV Elbows 1 30 2 30 1 30 2 30 1 70 2 50 1 70 2 50 Blower Transition Box Lo Fire Std Pressures of WC 5 No Elbows 1 20 1 90 1 20 1 90 1 20 1 90 1 30 2 30 40 5 90 DWV Elbows 1 00 1 80 1 00 1 80 1 00 1 80 1 20 2 20 Limits amp Controls Rollout Switch F Limit Control Setting F Fan Control Type HW ST9162A Fan Control On T Timed secs Off a Std Pressure Sw Part No 1013515 1013515 1013515 1013166 Blower Switc
30. W C o 7 5 55 For 100 1 amp A2 Models 4 Ton Units For 125 A1 amp A2 Models 5 Ton Units Tap Low Med L MedH Hi 06 5 amp 26 65 CNRC EL besii 6 ne 08 e 06 zm eee 69 TR BN NEL IN EUN Inches of W C External Static Pressure Inches of W C External Static Pressure For 075 A2 Models 3 5 Ton Units ose ves p ee os 7 ner es om ee e es oem owe em ps o 2 7 2 as EE ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 440 08 2002 02 53 Two Stage Multi Position Furnace HP DC Blower Motor 9 050 1 iagram D Service Manual Wirin 966101 Saaads 8 ONILWSH H3dOHd S3HOLIMS ONILSNPGV STVONVIW 33S AINO3 JAIM 00901 AdAL C39 V Id LSNW LI C3OV Ida ONISIM LINDYID TVNH3INI JHL GaliddNs SV TVNIOIHO 4 AYOLOVA 39VLIOA 39NVHO AHOLOV4 SO
31. W C If Propane gas has a different BTU content orifices MUST be changed by licensed Propane installer Measured input can NOT exceed rated input Any major change in gas flow requires changing burner orifice size CHECKING INPUT FIRING RATE Once it has been determined that the gas supply is correct to the furnace it is necessary to check the input firing rate This can be done in two 2 ways First by checking and ad justing as necessary the manifold Outlet pressure The second way is to Clock the gas meter 440 08 2002 02 Service Manual Two Stage Multi Position Furnace A WARNING CHECKING MANIFOLD PRESSURE 1 Connect manometer or Magnehelic gauge to the tapped opening on the outlet side of gas valve Use a Turn OFF gas at shut off before connecting manometer with a 0 to 12 minimum water column manometer range Fire or explosion hazard Failure to turn OFF gas at shut off before 2 Turn gas ON Operate the furnace on high fire by using connecting manometer can result in death a jumper wire on the R to W1 amp W2 thermostat connec personal injury and or property damage tions on the fan board 3 Remove the adjustment cover on the gas valve Turn adjusting screw counterclockwise to decrease the manifold pressure and clockwise to increase See Figure 4 4 Setthemanifold pressure to value shown in Table 1 or Table 2 5 Operate the furnace on low fire by using a jumper wire on the R to W1 thermosta
32. adjust the circulating blower speed Switches 4 and 5 adjust the heating speeds Switches 6 7 and 8 adjust the cooling speed See the Technical Service Data Sheet for the model you are servicing to obtain the switch settings for the desired airflow rates 440 08 2002 02 25 Service Manual Two Stage Multi Position Furnace Figure36 Blower Motor Control CONTINUOUS HEATING COOLING CFM SELECT CFM SELECT CFM SELECT 010 EXAMPLE Cooling Airflows Switches 6 7 amp 8 INPUT 000 3 5 Ton SIGNAL OR 001 3 0 Ton THERMOSTAT 010 2 5 Ton DIP CONNECTIONS 011 2 0 Ton SWITCHES IMPORTANT DO NOT CONNECT THIS CONTROL TO A PERMANENT SPLIT CAPACITOR MOTOR See Technical Support Manual for correct airflow ac LN rates NOTE Power must be completely OFF to unit any time switch settings are changed or settings will not take effect Heating Cooling amp Continuous Airflow Settings Continuous Blower 0 10 Static Lo Heat Air Temperature Adjustment F Furnace Model Furnace Model 708 821 s we re Factory Setting Factory setting Hi Heat Air Temperature Adjustment F Furnace Model Factory setting Approximate air temperature change from factory setting 0 20 static on high heat 440 08 2002 02 26 Two Stage Multi Position
33. air proving switch pressure switch is used on all models to insure that a draft has been established through the heat exchanger before allowing burner operation To insure continued SAFE RELIABLE operation NEVER SUBSTITUTE a pressure switch with one that is similar in appearance ONLY FACTORY PROVIDED or AUTHORIZED SUBSTITUTES ARE ACCEPTABLE All models installed at altitudes of 4 000 above sea level or higher require replacing the standard pressure switch with a high altitude pressure switch The different pressure switch settings allow continued SAFE RELIABLE high altitude operation Note Transition switch checks lo fire airflows amp blocked condensate Blower switch checks Hi fire airflow HIGH ALTITUDE PRESSURE SWITCHES ALL MODELS Max Close 125 1013157 Condensing _ 50 75 amp 100 140 W C 1 20 0 10 WC 1013165 1 70 1 50 0 10 W C Always check current Technical Support Manual for Part Nos Under normal operating conditions sufficient negative pres sure will be created to close the pressure switch and keep it closed to keep furnace operating Under abnormal condi tions however such as arestricted vent pipe or aleak in one of the heat exchangers sufficient negative pressure will not be created This will result in the switch failing to close or fail ing to remain closed during furnace operation 440 08 2002 02 12 Two Stage Multi Position Furnace Fig
34. be constructed of 3 4 PVC or CPVC pipe Vent Drain Connection The drain line must maintain a 1 4 per foot downward slope li toward the drain DO NOT trap the drain line in any other location than at the condensate drain trap supplied with the furnace If possible DO NOT route the drain line where it may freeze The drain line must terminate at an inside drain to prevent freezing of the condensate and possible property damage 1 condensate sump pump MUST be used if required by local codes or if no indoor floor drain is available The condensate pump must be approved for use with acidic condensate 25 23 63 2 Aplugged condensate drain line or a failed condensate pump will allow condensate to spill If the furnace is installed where a condensate spill could cause dam age it is recommended that an auxiliary safety switch be installed to prevent operation of the equipment in the event of pump failure or plugged drain line If used an auxiliary safety switch should be installed in the R circuit low voltage ONLY 440 08 2002 02 17 Service Manual The HONEYWELL ST9162A Electronic Fan Timer Fur nace Control is an integrated electronic control which con tains NO USER SERVICEABLE COMPONENTS addi tion to controlling the fan operation for heating it also takes the place of the blower relay combustion air relay and or system relay The ST9162A is used in con
35. box 11 Remove machine screws securing secondary heat ex changer inlet flange to lower partition Remove screws around perimeter of both the upper and lower partitions leaving the screws across the center of the two panels in place Primary Heat Exchanger can now be removed with both upper and lower partitions attached Reverse procedure to reinstall making sure that any gaskets that have been torn during disassembly are replaced with new ones After reassembly turn the gas supply on and check for leaks All leaks must be repaired immediately 16 Perform an operational check of the furnace Two Stage Multi Position Furnace Service Manual HONEYWELL SV9541Q SMART VALVE Sequence of Operation POWER APPLIED TO APPLIANCE THERMOSTAT CALLS FOR HEAT HI AND LOW AIR PROVING SWITCHES PROVED OPEN WAIT FOR PRESSURE SWITCHES TO OPEN COMBUSTION AIR BLOWER ON HIGH SPEED HI AND LOW AIR PROVING SWITCHES Ba COMBUSTION BLOWER DE ENERGIZED FIVE MINUTE WAIT PERIOD PROVED CLOSED WITHIN 30 SECONDS ve PRE PURGE AA PILOT VALVE OPENS THREE SECOND FLAME IGNITOR POWERED FAILURE RECYCLE DELAY PILOT LIGHTS AND FLAME IS SENSED 0 PILOT VALVE CLOSES DURING 90 SECOND TRAIL FOR PILOT IGNITOR OFF IGNITION t MAIN VALVE OPENS ON HIGH IGNITER OFF CIRCULATINGFAN ON AND COMBUSTION AIR BLOWER ON LO
36. but not for others Figure 28 Heating OFF Delay DIP switch Settings 140 Sec 180 Sec The ST9162A Heating Fan ON delay may be set to ei ther 30 or 60 seconds The control is shipped out at 30 se conds As with the OFF delay this may be satisfactory for some installations but not for others Heating ON Delay DIP switch Settings The OFF delay should be set as long as possible without creating COLD AIR complaints at the end of the cycle The delay should be set as short as possible without creating COLD AIR complaints at the beginning of the cycle The COOLING ON and OFF delays of the ST9162A are fixed at 5 seconds and 60 seconds respectively and are not adjustable Two Stage Multi Position Furnace Service Manual 21 ST9162A SV9541Q TESTING SEQUENCE If furnace successfully passes this testing sequence it can be assumed that there are no problems with the ST9162A SV9541Q CONTROL SYS TEM Ifit does not however it does not necessarily mean that there are problems with the control SYSTEM Any malfunctions should be thoroughly investigated before replacing any components CHECKING HEATING FUNCTIONS 1 JUMPER W1 or W1 amp W2 2 CHECK COMBUSTION BLOWER START UP 3 CHECK IGNITION SYSTEM ACTIVATION 4 WHEN MAIN BURNER LIGHTS CHECK HEATING FAN ON DELAY 5 CHECK HEATING SPEED FAN OPERATION 6 REMOVE JUMPER 7 CHECK POST PURGE DELAY 8 CHECK HEATING FAN
37. furnace Drain Line Transition Box Pressure Switch Transition Return Air Upflow Installations Dual Certified 9MPT amp 9MPV See Figure 43 Note For easier installation of the drain hoses and clamps to the condensate trap follow the directions outlined below except do not make any clamp connections to any of the drain stubs and hoses until the hose routing and lengths have been determined Remove the condensate trap and drain hoses from the furnace and secure the drain hoses to the drain stubs on the trap with the hose clamps position the clamps as shown in Figure 43 Install the condensate trap hose assembly to the furnace casing Hook one side of the clamp ears on the drain stub through the hole in the casing and push the condensate trap into position Secure with the two screws Reconnect the drain hoses to the stubs on the vent fitting and the plastic transition and secure with the clamps Mount the condensate drain trap in a vertical position to either the left or right side of the furnace using the two screws and gasket that are provided If needed remove the hole plugs from the furnace side panel and relocate to the open set of holes in the opposite side panel NOTE All gaskets and seals must be in place for sealed combus tion applications 440 08 2002 02 32 Ensure that the vent fitting and the 90 street elbow are securely at tached to the combustion blower using the c
38. marking arrow pointed toward the vent pipe with the drain stub at a 5 to 10 downward slope See Figure 44 Plug the upper drain stub on the vent fitting with the yellow plastic cap Service Manual For left side mounted condensate trap connect the 3 OD rubber hose with the 90 bend to the large drain stub on the condensate trap and secure with a 3 4 clamp Route the hose to the drain stub on the bottom ofthe plastic transi tion box Cut off excess hose and discard Connect the hose to the drain stub on the transition and secure with 3 4 clamp For right side mounted condensate trap connect the 3 4 OD rubber hose with the 90 bend to the bottom ofthe plastic transition box and secure with a 3 4 clamp Route the hose to the large drain stub on the condensate pump Cut off excess hose and discard Connect the hose to the drain stub on the condensate trap and secure with a 3 4 clamp Figure 44 Upflow Installations Dual Certified 9MPT amp 9MPV A2 Models RIGHT Side Venting 0 Supply Air Some Models have one pressure switch DRAIN SIDE VIEW Rotate downward 5 to 10 9 25 24 00 For left or right side mounted condensate the pressure tap on the condensate trap MUST be connected to the unused pres sure tap located on the upper right hand corner ofthe plast
39. sections on Gas pressure and pressure switches to obtain specific information for you particular installation altitude Burner Face 10 10 78 440 08 2002 02 Service Manual 10 CHECKING TEMPERATURE RISE Checking Temperature Rise Thermometer Return Air Temp Thermometer Supply Air Temp The furnace is designed to operate within a certain specified range of temperature rise Operating the furnace outside the specified range may result in lower efficiency and or comfort levels as well as prema ture combustion component failures Simply stated the temperature rise through the furnace is the difference in temperature between the return air and the supply air NOTE BEFORE CHECKING TEMPERATURE RISE BE CERTAIN THAT MANIFOLD PRESSURE IS PROPERLY ADJUSTED ALLOWABLE TEMPERATURE RISE FOR 11 ROOM THERMOSTATS Room thermostats are available from several different manufactures in a wide variety of styles They range from the very simple and inexpensive Bi metallic type to the complex They are simply a switch or series of switches designed to turn equipment or components ON or OFF at the de sired conditions 440 08 2002 02 Two Stage Multi Position Furnace 2 STAGE MODELS Weds Fre 50 Mbtu H 35 F 65 F 25 F 55 F 40 F 70 F stud LE 30 F 60 F Always check current Technical Support Manual ALLOWABLE TEMPERATURE RISE FOR VARIABLE SPEED MODELS Modi Fi
40. tent operation The roll out switch monitors the temperature inside the burn er box and interrupts furnace burner operation when its temperature indicates flame roll out has occurred If the roll out switch has opened the cause must be deter mined Some possible reasons for flame roll out include a re stricted primary or secondary heat exchanger or over fired furnace MANUAL RESET SWITCH MODELS Furnace models which are equipped with a Honeywell ST9162A Fan timer furnace control use a manual reset roll out switch Once the roll out switch has opened burner op eration will be prevented until the roll out switch is Manually Reset by pressing the red button located on the switch While the roll out switch is open Depending upon the partic ular model the combustion blower and or circulating blower will be energized continuously 440 08 2002 02 Service Manual 14 PRESSURE SWITCHES TRANSITION PRESSURE SWITCH Under normal operating conditions sufficient pressure is de veloped by the exhaust combustion blower to close the switch and permit the burner to operate As the condensate drain begins to back up however the pressure begins to re duce Whenthe pressure drops sufficiently burner operation will be prevented until the condition is corrected STANDARD PRESSURE SWITCHES ALL MODELS Max Close Condensing E Always check current Technical Support Manual for Part Nos BLOWER PRESSURE SWITCH An
41. thermostat should not be mounted where it may be af fected by drafts discharge air from registers hot or cold or heat radiated from the sun of appliances Never install in al coves bathrooms or bedrooms The thermostat should be located about 5 ft above the floor in an area of average temperature with good air circulation Normally an area in close proximity to the return air grille is the best choice Mercury bulb type thermostats MUST be level to control tem perature accurately to the desired set point Electronic digi tal type thermostats SHOULD be level for aesthetics HEAT ANTICIPATORS Heat anticipators are small resistance heaters built into most electric mechanical thermostats Their purpose is to pre vent wide swings in room temperature during furnace opera tion In orderto accomplish this the heat output from the anticipa tor must be the same regardless of the current flowing through it Consequently most thermostats have an adjust ment to compensate for varying current draw in the thermo stat circuit The proper setting of heat anticipators then is important to insure proper temperature control and customer satisfac tion The best method to obtain the required setting for the heat anticipator is to measure the actual current draw in the con Service Manual trol circuit using a low range 0 2 0 Amps Ammeter See Figure 10 After measuring the current draw simply set the heat ant
42. voltage to the furnace should be checked WITH THE FURNACE IN OPERATION Voltage readings outside the specified range can be expected to cause operating problems Their cause MUST be investigated and corrected ELECTRICAL GROUND Grounding of the electrical supply to ALL FURNACES IS REQUIRED for safety reasons POLARITY CORRECT POLARITY of the line voltage supply to all fur naces is also REQUIRED for safety reasons CHECKING GROUNDING AND POLARITY Grounding may be verified as follows 1 Turn the power supply OFF 2 Using an Ohmmeter check for continuity between the Neutral white wire and Ground wire green of the supply circuit 3 Withthe Ohmmeter set on the R x 1 scale the reading should be zero Ohms 4 A zero Ohm reading indicates that the neutral is grounded back to the main panel 440 08 2002 02 Two Stage Multi Position Furnace 7 The Combustion Blower Assembly is mounted on the outlet side of the Secondary heat exchanger This blower creates a partial vacuum negative pressure within the heat exchangers drawing the flue products out of the furnace 5 An alternate check would be to check for continuity from the Neutral to a cold water pipe Pipe must be metal and must have a continuous uninterrupted con nection to ground to a continuous uninterrupted connection to ground or to a driven ground rod 6 Anyreadings otherthan zero Ohms would indicate a poor ground or no ground L
43. when Cool fan speed is on Cool Y mode 1 4 QC s EAC Electronic Air 115 VAC Present when High Heat Low Heat or Cool fan speed is 1 4 Cleaner power on CONSTANT FAN Continuous Fan 115 VAC Present when other fan speeds are on 4 QC s power IND IN Inducer motor power from 115 VAC Present when Induced draft blower motor is on Heat 4 Smart Valve modes Open Limit mode IND LOW Inducer motor power from 115 VAC Present when Induced draft blower motor is on Heat 3 146 Smart Valve modes Open Limit mode HUM Humidifier power 115 VAC Present when the High Heat or Low Heat fan speeds 1 4 QC s are on 2 pin 2 High Fire solenoid supply 24 VDC low fire Voltage is always present when 24 VAC transformer is connects to one side of 16VDC high fire powered The signal is actually 1 2 wave rectified high pressure switch riding on top of DC voltage The DC voltage readings given are approximate when measured with a Fluke 79 digital multimeter or equivalent To achieve high fire energize the high fire solenoid the high pressure Switch must be closed and the ST9162 fan board must turn on a transistor 24 VAC 24 VAC Present when the door interlock switch is closed pin 5 Date Line Non periodic 1 2 wave rectified AC Present when the door interlock switch is closed measures as an unstable AC volt age bouncing between 12 VAC and 16 VAC pin 1 pin 3 pin 4 pin 5 P1 pin
44. 1 5 0 0 e 011 600 100 101 110 111 400 200 0 0 1 0 2 0 5 0 7 1 ESP W C Figure 6 9MPVO075 Lo HEAT CFM VS EXTERNAL STATIC PRESSURE 1400 1200 1000 000 E 1 O 800 010 o 011 9 100 101 609 110 111 400 200 0 0 1 0 2 0 5 0 7 1 ESP W C 440 08 2002 02 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 48 Two Stage Multi Position Furnace Service Manual Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Figure 7 9MPV100 COOLING CFM VS EXTERNAL STATIC PRESSURE 2500 2000 000 1500 01 010 5 1 100 101 1000 110 111 500 0 0 1 0 3 0 5 0 7 1 ESP W C Figure 8 9MPV100 Hi HEAT CFM VS EXTERNAL STATIC PRESSURE 2500 2000 000 1500 001 2 010 011 0 100 1 1000 110 111 500 0 0 1 0 2 0 3 0 5 0 7 1 ESP W C ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 440 08 2002 02 49 Service Manual Two Stage Multi Position Furnace Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings
45. 1 request is still present after the selected Low Fire Delay time expires 12 minutes the inducer switches to high speed the high fire solenoid energizes and the fan switches to High Heat speed W1 signal removed from EFT The gas valve de energizes and the main burners go out The inducer runs at its present speed for a 5 second postpurge period The fan switches to or stays at Low Heat speed Timed from the gas valve de energizing the Low Heat fan speed de energizes after the selected Heat Fan Delay time expires NOTE4 If a new Heating request arrives while the control is High Heat until the Heat Fan Off Delay expires or the Heat Fan waiting in the Heat Fan Off Delay time the fan speed switches to On Delay expires for the new Heating request Heating Request two stage thermostat operation 4th DIP switch must be in on position see furnace wiring diagram 24 VAC signals applied to W1 terminal of EFT control Sameresponse as single stage thermostat operation described above except the control will not go to high fire High Heat fan speed unless a W2 signal is applied 440 08 2002 02 20 Two Stage Multi Position Furnace Service Manual 24 VAC signals applied to W1 and W2 terminals of EFT control Samelight off routine as described for the signal stage thermostat operation exceptthat atthe end ofthe selected Heat Fan On Delay the inducer remains on high fire the high fire solenoid remains energized and the High Heat
46. 42 Two Stage Multi Position Furnace Service Manual SV9541Q ELECTRICAL VARIATION 2 STAGE Con t Connector Pin 4 Voltage Signal When Signal is Present Present when the door interlock switch is closed Same rectified AC signal as P1 pin 5 Present when the 24 VAC transformer is powered 24 Present when the door interlock switch is closed 2 24 Present when the door interlock switch is closed HSI return 24 VAC with igniter present Present when HSI is not turned on When HSI is on this signal is 0 VAC to 10 VAC depending on input line volt age potential HSI supply 24 VAC Present when the door interlock switch is closed 580 Present when the door interlock switch is closed Inducer supply 115 VAC Present when the inducer draft blower motor is on Heat modes Open Limit mode 115 VAC Present when the door interlock switch is closed C3 pin 3 0 VAC Always present neutral connection C3 pin 4 L2 neutral 0 VAC Always present With a motor tap connected voltage appears at unpowered fan termi ducer motor is running due to feedback through the motor windings nals whenever the motor is running due to feedback through the motor wind ings NOTE1 Using Fluke 79 digital Multi Meter DMM 1 2 wave rectified AC voltage typically measures about 14 VAC The Fluke 79 is not a true RMS Voltage appears on the unpowered inducer terminal whenever the in meter 440 08 2002 02 43
47. 6 R o O 24 VAC Present when the door interlock switch is closed pin 8 pin 9 pin 1 pin 2 P1 pin 8 High Fire solenoid return wave rectified AC Present when the door interlock switch is closed This line voltage increases when the high fire solenoid circuit is energized C xfmr common 0 VAC Always present P DC motor control signals See memo on DC motor signals See memo on DC motor signals C1 pin 1 Limit return wave rectified AC Present when the door interlock switch is closed This voltage decreases when a limit switch is open C1 pin 2 Low Pressure Switch wave rectified AC Present when the door interlock switch is closed This supply signal is the same as the C1 pin 1 C1 pin 3 Low Pressure Switch 1 2 wave rectified AC Present when the door interlock switch is closed This return AC voltage decreases when the Low Pressure Switch closes With a motor tap connected voltage appears at unpowered fan terminals whenever the motor is running due to feedback through the motor windings P1 P1 P1 Line Voltage 115 VAC Present when the door interlock switch is closed P1 1 1 1 1 Voltage appears on the unpowered inducer terminal whenever the inducer motor is running due to feedback through the motor windings NOTE1 Using Fluke 79 digital Multi Meter DMM 12 wave rectified AC voltage typically measures about 14 VAC The Fluke 79 is not a true RMS meter 440 08 2002 02
48. CONTROL WIRING S isset eps qo ne aee dte ate e to bdo eds bes ue bs 10 SWI GHES iu Reduces tege Es adt van t 10 14 PRESSURE SWITCHES 5555 m redd e poe GU RES PSS SUCH ERU CORE OR 12 15 VENT COMBUSTION AIR PIPING REX CREE 13 16 STANDARD VENT TERMINATION 14 17 CONCENTRIC VENT TERMINATION 16 18 EXHAUST BLOWER XU a SU ERG ERU S DATI 17 19 CONDENSATEDRAINTR P ane Br ee ples Renae 17 20 HONEYWELL ST9162A FAN TIMER FURNACE CONTROL 18 21 ST9162A SV9541Q TESTING SEQUENCE 19 22 HONEYWELL SV9541Q 2 STAGE GAS VALVE IGNITION SYSTEM 19 23 HONEYWELL SV9541Q SYSTEM OPERATION 20 24 CHECKING FLAME CURRENT 22 25 CAPACITORS e eaves is e eso Re prit 22 2B BLOWEH ASSEMBLY Ete PA 22 27 BEOWERROT TION 2 531 vale Fav DEA de FC RE 27 28 HEAT EXCHANGER REMOVAL REPLACEMENT 38 SV9541G SMART VALVE Sequence of Operation 39 SV9541G SMART VALVE Trouble shooting 40 V9541Q SMART VALVE Electrical Variation
49. Furnace 2 SPEED MODELS P S C MOTOR HEATING SPEEDS Should it be necessary to change blower speeds to obtain proper temperature rise on either or both High fire and or Low Fire Simply take the appropriate speed tap wire and plug it on to the terminal marked HEAT HIGH or HEAT LOW respectively on the HONEYWELL ST9162A control 2 Speed Models 9064 Blower Speed Taps Low COOLING SPEED When the proper speed has been determined simply plug it on to the terminal marked COOL on the HONEYWELL ST9162A control M1 amp M2 TERMINALS There are two 2 terminals marked M1 amp M2 on the HONEYWELL ST9162A control which have no internal 27 BLOWER ROTATION The startup of a furnace will involve a cycle or two of the fur nace to properly prime the condensate trap with water Until the trap is fully primed some condensate will be pulled into the combustion blower The furnace may cycle on the pres sure switch connected to the plastic transition box due to con densate buildup After the trap is primed the condensate will start draining from the furnace The combustion blower will clear out any remaining condensate in the blower housing through the vent fitting downstream of the blower Note that the condensate trap can also be primed by pouring water into the vent drain side of the trap Remove the small plastic cap and clamps from the unused drain stub on the vent drain side ofthe condensate trap
50. G terminals of EFT control Low motor speed energized without delay G signal removed from EFT Low motor speed de energized without delay NOTE1 Furnaces with DC blower motors run a low circulating fan speed in response to G request NOTE2 Furnaces with PSC blower motors de energize the Low Heat fan speed during the heat exchanger warm up period on a call for Heating that occurs during a G request NOTES Heating or Cooling requests received during a Fan request cause the fan speed to change to the appropriate heat or cool speed after the selected Fan On Delay time expires The fan returns to circulating speed after the selected Fan Off Delay time expires following loss of the Heating or Cooling request Heating W1 Request single stage thermostat operation 4th DIP switch must be in off position see furnace wiring diagram 24 VAC signals applied to W1 terminal of EFT control Inducer motor turns at high speed The high fire solenoid energizes Following a 3 second prepurge delay the pilot valve opens and the ignitor begins to warm up After the pilot lights the main burners energize and light burners now at high fire rate Timed from the opening of the main gas valve the control will delay the selected Heat Fan On Delay time before switching the inducer to low speed de energizing the high fire solenoid and the fan switches to Low Heat speed e Timed from initial application of the Heating request if the W
51. MULTI POSITION 2 STAGE GAS FURNACES Service lt 9MPT amp 9 amp 2 This manual supports condensing gas furnaces manufactured in 2001 Manufactured by IB Part Number 440 08 2002 02 Bodies 2001 International Comfort Products Corporation USA 4 2002 9MPT Dual Certified Venting 1 or 2 pipes 9MPV Dual Certified Venting 1 or 2 pipes Variable Speed 2001 International Comfort Products Corporation USA 1136 Heil Quaker Boulevard LaVergne TN 37086 All rights reserved throughout the World Two Stage Multi Position Furnace Service Manual TABLE OF CONTENTS T INTROD GTION a ro p 26074 AR Rebelde Rot Pr As PS eR act 2 2 UNIT IDENTIFICATION gt Tue sco EIU D 2 3 FURNACE THEORY OF OPERATION f nti rnnt va e tne n a 3 aA ELECTRICAL SUPREN ateists cea erroe S 4 5 aitas Ere EER 5 p CPP A EVE m ei RI 5 ZoabPSPRHESSUDBE EA n E SOR EESTI E RATER Bo ON 7 8 HIGH ALTITUDE OPERATION 7 9 BURNERS centus 0 torte ea 7 10 CHECKING TEMPERATURE RISE 2 6004 5 8 11 ROOM THERMOSTATS garies newer dta nee Sara 8 9 12
52. Pointed OUT dwg 25 23 562s 28 insert into furnace Trap Connection Downflow Installations Dual Certified 9MPT amp 9MPV Models See Figure 47 Note For easier installation of the drain hoses and clamps to the condensate trap follow the directions outlined below except do not make any clamp connections to any of the drain stubs and hoses until the hose routing and lengths have been determined Remove the condensate trap and drain hoses from the furnace and secure the drain hoses to the drain stubs on the trap with the hose clamps 440 08 2002 02 36 position the clamps as shown in Figure 47 Install the condensate trap hose assembly to the furnace casing Hook one side of the clamp ears on the drain stub through the hole in the casing and push the condensate trap into position Secure with the two screws Reconnect the drain hoses to the stubs on the vent fitting and the plastic transition and secure with the clamps Two Stage Multi Position Furnace Mount the condensate drain trap in a vertical position to either the right or left side ofthe furnace using the two screws and gasketthat are provided If needed remove the hole plugs from the furnace side panel and relocated to the open set of holes in the opposite side panel NOTE All gaskets and seals must be in place for sealed combus tion applications For both rightand leftside vent remove the 90 street elbow from the vent fitting by loosening
53. Pressure Switch Blower Hi Fire Transition Box Return Air DRAIN SIDE VIEW Two Stage Multi Position Furnace Upflow Installations Dual Certified 9MPT amp 9MPV A1 Models 0 RIGHT Side Venting Rigid Plastic Drain Tube 662 Rubber Hose Upflow Installations Dual Certified 9MPT amp 9MPV See Figure 39 Mount the condensate drain trap in a vertical position to either the left or right side ofthe furnace using the two screws and gasketthat are provided If needed remove the hole plugs from the furnace side panel and relocate to the open set of holes in the opposite side panel Drill two 7 64 diameter holes in the casing using the conden sate trap as the template Ensure thatthe vent fitting and the 90 elbow is securely attached to the combustion blower This configuration allows left side venting from the furnace If right side venting is required the combustion blower must be relocated on the plastic transition box Remove the four 4 screws that secure the blower to the transition Rotate the blower 180 and secure with the four 4 screws Use caution to notovertighten the screws to pre vent stripping out of the plastic mounting holes For right side venting remove vent fitting assembly from combus tion blower Remove 90 elbow and rubber tubing from the vent fit tin
54. T TYPE SINGLE STAGE mu H 1234 1234 1234 1234 1234 0 8 A MAX COMBINED HEAT ON DELAY 51 180 SEC d 5 gt 0 2 gt lt LL 140 SEC HEAT OFF DELAY 100 SEC H zz 1234 1234 1234 COOL ON DELAY 5 SEC COOL OFF DELAY 60 SEC 52 9L iagram 1 HP DC Blower Motor 9MPV075 100 amp 125 A1 Two Stage Multi Position Furnace Wirin YO JAIM 20501 41 MV Q39V Id3 LSNW LI JHL JO LSNW JHL 5 SV 38IM 38 UEEEEELE AIRFLOW 5 HOLIMS 4 55 4 NO 31535 NI OL HOLIMS LNOTION NIV INVHOVIG JOMINOO ionen E 63 Lt UALINO L avg SG33dS ONILVINONID 9 ONI1009 SNILV3H H3dOd SAHOLIMS ONILSNPAV STVANVW 335 LINDYIO WNYSLNI MOTI3A AHOLOV4 91514 ADVLIOA AHOLOVA tonn Eh 1 M 1 000 1 0202080 WOSN3S 120 VAG LINE MTR WJINHOJSNVHL seq 51 69 S7300 d HOLIMS
55. VLIOA N3349 NMO38 ania 3009 40109 2 STAGE THERMOSTAT TYPE 1VISOWBH3HL 4 LV LSIGINNH 15 6 SINGLE STAGE YOLOW HOLIMS aunssaud Oz Or Os 9 O6 Or B gens 11 WOSN3S 6 69 1 s Lavz ess S13dOW INOS MOLIOVdVO a 1 gt lt zl 2 lt t IN t IN t N IN N 3snave EAC HUM 0 8 A MAX COMBINED NO SNIGN3d3G S3lH3S OL L HOLIMS LNOTION NIV 180 SEC YAWYOASNVYL ANVGNODAS MAWYOASNVYL EW ASL O asni vs ANO STSGOW d7 SYOLONGNOD L65 91314 170A IH HOLIMS 4 FAN CONTROL MODULE S1 140 SEC HEAT OFF DELAY 100 SEC Pa 1234 1234 60 SEC HOLIMS HOLIMS Baon saias MOOTYALNI NI OL HOLIMS LNOTION INN COOL ON DELAY 5 SEC COOL OFF DELAY 60 SEC NOILOANNOO 91913 ONIOIAH3S 3HOJ38 LO3NNOOSIG INVHOVIO NOLLO3NNOO FACTORY SETTING ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL 54 THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 440 08 2002 02 Service Manual 2 STAGE THERMOSTA
56. W SPEED MAIN VALVE ON LOW FIRE AFTERDELAY 2 CIRCULATING AIR FAN OFF FLAME SENSE LOST PILOT AND MAIN VALVE CLOSE AFTER DELAY NO THERMOSTAT CALL FOR HEAT ENDS FLAME SENSE LOST MORE THAN FIVE COMBUSTION AIR BLOWER OFF AFTER TIMES IN THIS CALL FOR HEAT NO POST PURGE PILOT AND MAIN VALVE CLOSE YES 1 Ignitor turns OFF about 30 seconds into the trial for ignition If the pilot flame has EE not lit it turns back ON for the final 30 seconds of the 90 second trial for ignition valuisse ee PETER The pilot valve is energized during the entire trial for ignition This is normal opera tion for the gas ignition system 2 Ifa W2 call for heat is present circulating fan on high speed Combustion air blower CIRCULATING AIR FAN OFF AFTER and main valve remain on high DELAY NOTE If main limit string opens and takes longer than 2 minutes to close system goes into 1 hour wait period WAIT FOR NEXT CALL FOR HEAT 440 08 2002 02 39 Service Manual Two Stage Multi Position Furnace HONEYWELL SV9541Q SMART VALVE Trouble shooting The 6 X designation indicates a combination of flash codes 6 flashes shows the control is in soft lockout followed by X flashes to indicate the reason the control went into soft lockout Last status code indicates repair to address first LED STATUS INDICATES CHECK REPAIR Heartbe
57. and the cable that attaches to the sys tem control The hot surface element is made of a tough break resistant ceramic composite material It operates on 24 Volts A C The Igniter Flame Rod assembly can be replaced indepen dently from the pilot burner assembly The hot surface igniter can be checked for resistance A Good igniter will have a resistance of 10 Ohms or less Flame current for this system should be 2 0 microamps or higher Carrier voltage for flame signal i e flame rod to valve body is 80 volts or higher 440 08 2002 02 Service Manual Two Stage Multi Position Furnace 23 HONEYWELL SV9541Q SYSTEM OPERATION amp DIAGNOSTICS The following is the normal operating sequence for the 2 stage control system Cooling Y Request 24 VAC signals applied to Y amp G terminals of EFT electronic fan timer control Cool motor speed energized after 5 second Cool Fan On Delay time Y amp G signals removed from EFT Cool motor speed de energized after 60 second Cool Fan Off Delay time Cooling Y and dehumidification Y2 requests 24 signals applied to Y Y2 amp G terminals of EFT electronic fan timer control Same operation as the cooling Y request except the cooling speed is reduced 2096 to compensate for high humidity conditions during cooling operation The cooling speed returns to the normal setting after the Y2 signal is removed Circulating Fan G Request 24 VAC signals applied to
58. at Bright Dim 2 Flashes 3 Flashes 5 Flashes 6 Flashes 1 Flash 6 Flashes 2 Flashes 440 08 2002 02 No power to system control Normal indication whenever the system is powered unless some abnormal event has occurred Low pressure switch closed when it should be open i e when call for heat begins Combustion blower is not energized until pressure switches opens Low pressure switch open when it should be closed i e longer than 30 seconds after combustion blower inducer is energized System goes into 5 minute delay period with com bustion blower inducer off At end of the 5 minute delay another cycle will begin Main Limit or Roll Out Switch is open Combustion blower is energized Circulating blower is energized heat speed Flame signal sensed out of proper sequence Combustion blower is energized Circulating blower is energized heat speed after the ON delay Soft Lockout Failed to light pilot during 90 sec trial for ignition Combustion air blower is de energized Circulating blower is de energized after the OFF delay After 5 minute delay time control system will reset and initiate a new ignition sequence Soft Lockout Last failure was Flame Sense lost during run Maximum recycle count exceeded Combustion air blower is de energized Circulating blower is de energized after the OFF delay After 5 minute delay time control system w
59. ation the furnace will operate on low fire for 12 minuteslf the heat request exists for more than 12 minutes If the heat request exists for more that 12 minutes the furnace will auto matically shift to the high fire mode for the remaining duration of the heating cycle For two stage thermostat installations the R W1 and W2 wires from the thermostat connect to the R W1 and W2 connections on the furnace control During 13 LIMIT SWITCHES Two 2 different kinds of limit switches are used on this se ries of furnaces They are the main limit and roll out limit switches The main limit and roll out limit switches are used on all models NOTE limit switches are safety devices and other than for testing purposes should never be jumped out Limit switches are normally closed electrical switches de signed to open when their predetermined limit setting has been reached It should also be remembered that when a limit switch opens it more than likely is not due to a bad switch The cause of the opening limit must be found and corrected be 440 08 2002 02 10 Two Stage Multi Position Furnace operation the furnace will shift from low fire to high fire as requested by the thermostat The thermostat heat anticipa tors should be adjusted to a 10 setting for both types of ther mostats Low voltage connections to furnace must be made on termi nal board to fan control The ELECTRONIC CONTROLS used on this series RE
60. e vent fitting and secure with 5 8 clamp Route the hose to the smaller stub on the condensate trap Cut off excess hose and discard Connectthe hose to the drain stub on the trap and secure with 5 5 clamp NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage 440 08 2002 02 Service Manual Two Stage Multi Position Furnace Upflow Installations Dual Certified amp 9MPV A2 Models NOTE TRAP MUST BE PRIMED BEFORE OPERATION Yellow Plastic Cap Vent Pipe Supply Air Rubber Coupling amp Clamps Vent Pipe Grommet Vent Fitting TOP Venting Combustion Air Pipe optional dow nward 20 030 B V Air Intake Coupling amp Clamps 11 Section PVC Pipe Combustion Blower Mounting Screws 4 Gas Pipe Grommet Plastic Cap Some Models have one pressure switch 90 Street Elbow 1 Sla Hose amp Clamps Combustion Blow Plastic o Pressure Switch Hose Blower T gt Pressure Switch Blower Pressure Switch Hose Transition Trap Connection Clamp ears Pointed OUT Condensate Trap amp Gasket Left or Right Side Preassemble amp insert into
61. ed the capacitor s value in microfarads rather than with an Ohmmeter The reason forthis is that an Ohmmeter test can only indicate if a capac itor is OPEN or SHORTED it cannot verify if its value mi crofarads is within an acceptable range Capacitor should test to within 10 of its rated value Capac itors testing outside this range should be replaced A weak capacitor can be the cause of a motor failing to start be checked accurately using traditional methods An Ohmmeter test will tell or nothing about the condition of the motor Because of this a Special test method is required to determine if the motor is good or bad The condition of this motor can ONLY be verified as fol lows With the thermostat calling for operation in the de sired mode and line voltage applied to the motor Check for 24 Volts across the Common Blue wire and the de sired Speed wire of the six 6 pin connector at the motor With 24 VAC present motor should run If the motor Does Not run it is faulty and must be replaced If 24 VAC is not present a problem is indicated in the thermostat wiring or ST9162A Two Stage Multi Position Furnace Service Manual Variable Speed Models D C Motor Speed Wires GOP Function enabled only when energized with cooling speed Motor runs at 80 of cooling speed 2 Speed Models P S C Motor The P S C motor used in 2 speed models may be checked using traditional Ohmmete
62. emoves additional heat from the flue gasses causing their temperature to drop below dew point thus increasing operating effi ciency of the furnace and the term Condensing Fur nace This results in the forming of condensation wa ter which then must be routed to a drain 4 The placement of the secondary heat exchanger at the outlet of the primary heat exchanger creates additional resistance to the flow of gasses 5 To overcome the resistance to convective flow of the Primary and Secondary heat exchangers requires the use of an Induced Draft Combustion Blower Assembly 440 08 2002 02 Service Manual 6 The Combustion Blower Assembly is mounted on the outlet side of the Secondary heat exchanger This blower creates a partial vacuum negative pressure within the heat exchangers drawing the flue products out of the furnace 4 ELECTRICAL SUPPLY WARNING Electrical shock hazard Turn OFF electric power at fuse box or service panel before making any electrical connections and en sure a proper ground connection is made before connecting line voltage Failure to do so can result in death personal injury and or property damage SUPPLY CIRCUIT The furnace cannot be expected to operate correctly unless itis properly connected wired to an adequately sized 15 amp single branch circuit SUPPLY VOLTAGE Supply voltage to the furnace should be a nominal 115 volts It MUST be between 97 volts and 132 volts Supply
63. ent exhaust pipe to carry flue products to the outside of the structure Direct VENT ONLY models require a combustion air inlet to bring in all air for combustion from outside the struc ture 440 08 2002 02 Service Manual DUAL CERTIFIED models require a combustion air inlet pipe to bring in all air for combustion from outside the struc ture only when installed as a Direct Vent Furnace Two Pipe Installation 16 STANDARD VENT TERMINATION Vent Combustion Air Piping Charts Single Piping Chart Pipe Diameter Table Table Single Piping ONLY 50 000 amp 75 000 Btuh Furnaces 40 amp 5 90 elbows with 2 PVC pipe 100 000 amp 125 000 Btuh Furnace 40 8 5 90 elbows with 3 PVC pipe Elbows are DWV Long Radius Type for 2 and 3 vents If more than five elbows are required reduce the length of both the inlet and exhaust pipes 5 for each additional elbow used NOTE It is allowable to use larger diameter pipe and fitting than shown in the tables but not smaller diameters than shown Dual Piping Chart Pipe Diameter Table Tables Dual Piping ONLY 50 000 amp 75 000 Btuh Furnaces 40 amp 5 90 elbows with 2 PVC pipe 100 000 amp 125 000 Btuh Furnace 40 8 5 90 elbows with 3 PVC pipe Elbows are DWV Long Radius Type for 2 and 3 vents If more than five elbows are required reduce the length of both the inlet and exhaust pipes 5 1 5m for each additional elbow used
64. fan speed energizes NOTES The EFT control responds without delay to the presence or loss of W2 with W1 constant amp W2 results in high inducer high fire and High Heat fan speed W1 only results in low inducer low fire and Low Heat fan speed Heating Request with Gas Supply Line Shut Off 24 VAC signals applied to W1 terminal of EFT control Inducer motor turns on at high speed The high fire solenoid energizes Following a 3 second prepurge delay the pilot valve opens and the ignitor begins to warm up The ignitor glows red hot for 30 seconds then turns off The igniter stays off for 25 seconds then begins to warm up again The igniter glows red hot for 30 seconds then turns off e The pilot valve closes seconds after the igniter de energizes The inducer de energizes 5 seconds after the pilot valve closes The SmartValve proceeds to soft lockout and flashes error code 6 The control exits soft lockout after 5 minutes and begins another ignition sequence Gas Valve Diagnostic Codes See Figure 4 OFF E Control not powered Heartbeat Normal Operation Standby or call for heat 1 Flash Not used 2Flashes Low Pressure switch closed when should be open 3Flashes Low Pressure switch circuit was still sensed as open 30 seconds after the inducer was energized System is in 5 minute delay mode with inducer off After 5 minute delay a new ignition sequence will be initiated Note SV9541Q O
65. fitting with the yellow plastic cap Connect the 5 8 OD rubber hose with the 90 bend to the lower drain stub on the vent fitting and secure with a 5 8 clamp Route the hose to the horizontal drain stub on the condensate trap Cut off excess hoses and discard Connect the hose to the drain stub on the condensate trap and secure with a 5 8 clamp Connectthe 3 4 OD rubber hose with the 90 bend to the large drain stub on the condensate trap and secure with a 3 4 clamp Route the hose to the drain stub on the bottom ofthe plastic transi tion box Cut off excess hose and discard Connect the hose to the drain stub on the transition and secure with a 3 4 clamp The pressure tap on the condensate trap MUST be connected to the unused pressure tap located on the top of the plastic transition box Remove the plastic caps from the pressure taps on the con densate trap and the plastic transition and connect with the 5 45 OD rubber hose NOTE This will require drilling 5 46 OD hole in the furnace casing next to the condensate trap NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage Two Stage Multi Position Furnace Service Manual Figure 46 Horizontal Right Installations Dual Certified 9MPT amp 9MPV A2 Models NOTE TRAP MUST BE PRIMED BEFORE OPERATION tate downward 27 030 Vent Pipe Gas Pipe Combustion Yellow Grommet Air Pipe
66. g by loosening the clamp on the vent fitting Securely attach vent fitting directly to combustion blower NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope 440 08 2002 02 28 Plug the right drain stub ofthe ventfitting with the rubber plug Usea blunt pointed screwdriver to push the plug into the stub For left side mounted condensate trap connect the 3 4 OD rubber hose with the 90 bend to the drain stub on the bottom ofthe plastic transition box and secure with a 3 4 clamp Route the hose to the large drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with a 3 4 clamp For right side mounted condensate trap the rigid plastic drain tube MUST be used Cut two 2 long sections from the 3 4 OD rub ber hose Connectthe plastic drain tube to the drain stub on the bot tom of the plastic transition box and to the stub on the condensate trap using the two hose sections and 3 4 clamps NOTE The support leg on the plastic drain tube MUST be posi tioned on the blower partition Connect the 5 8 OD rubber hose with the 90 bend to the left drain stub on the vent fitting and secure with 5 g clamp Route the hose to the small drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure wit
67. h 5 8 clamp NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage Two Stage Multi Position Furnace Figure 40 Vent Pipe A Combustion Air Pipe optional Air Intake Coupling Plastic Caps Transition Box Service Manual Horizontal Left Installations Dual Certified 9MPT amp 9MPV A1 Models Pressure Switch Hose Blower Pressure Switch Blower Hi Fire Pressure Switch Transition Lo Fire Vent Fitting amp Clamps MMS 90 Elbow Combustion Blower Return Air Combustion Blower Mounting Screws 4 Pressure Switch Hose Ner Transition 3 4 Hose amp Clamps S X Vent Pipe Grommet DRAIN SIDE VIEW 1 Gas Pipe Grommet Rotate downward 20 to 30 Rubber Coupling amp Clamps Condensate Trap amp Gasket 5 g Hose amp Clamps Drain Line Plastic Caps dwg 25 23 54a Horizontal Left Installations Dual Certified 9MPT amp 9MPV See Figure 40 Relocate the plastic caps and clamps on the condensate drain trap from the vertical drain stub to the horizontal drain stubs Secure the clamps tightly to
68. h personal injury and or property damage The specific functions of the two 2 limit switches used in this series of furnaces are as follows Two Stage Multi Position Furnace MAIN LIMIT SWITCH A Normally Closed switch located on the front partition of the furnace It monitors supply air temperature and inter rupts furnace burner operation when a supply air tempera ture is sensed which would result in the furnace exceeding Maximum allowable outlet air temperature While the main limit is open combustion blower and or the circulating blow er will be energized continuously This control is an Auto matic reset control which will reset itself when the tempera ture sensed drops to a safe level If furnace burner cycles on this limit switch I E switch opens and closes during furnace operation it is more than likely due to a high temperature rise through the furnace See checking temperature on page 8 of this manual High temperature rise can be caused by either OVER FIRING high manifold pressure incorrect orifices etc or LOW AIR FLOW dirty filter blower speed too low excessive static in duct system etc Figure tt Typical Limit Switch lt A LON To verify this the cut out opening point of the switch should be checked using a thermocouple type thermometer con nected to the face of the switch as follows 1 Operate furnace for several minutes 2 Block return air grille s to furnace
69. h Pressure Close 0 95 0 95 0 95 1 30 Blower Switch Pressure Open 0 80 0 80 0 80 1 10 Transition Switch Pressure Close 1 70 1 70 1 70 1 80 Transition Switch Pressure Open 1 50 1 50 1 50 1 60 High Altitude Pressure Sw Part No 1013165 1013165 1013165 1013157 Blower Switch Pressure Close 0 70 0 70 0 70 0 85 Blower Switch Pressure Open 0 55 0 55 0 55 0 70 Transition Switch Pressure Close 1 40 1 40 1 40 1 70 Transition Switch Pressure Open 1 20 1 20 1 20 1 50 Blower Data Type amp Size 11 8 11 10 11 10 11 10 Motor Amps Rpm 9 8 1050 8 9 1080 11 2 1150 11 2 1150 Motor Type H p 1 5 Filter 16x25x1 16x25x1 16x25x1 16x25x1 2 Min Cool Cap Tons 1 5 1 5 2 2 Max Cool Cap Tons 3 3 5 5 Gas Conversion Kits All Models Nat to LP 1011789 LP to Nat 1011787 Order from Service Parts 440 08 2002 02 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 44 Two Stage Multi Position Furnace Service Manual Circulation Air Blower Data 9MPV A1 amp A2 Heating Cooling amp Continuous Airflow Settings Continuous Blower 0 10 Static Lo Heat Air Temperature Adjustment F Furnace Model Furnace Model 708 821 v ws wm ve Factory Setting Hi Heat Air Temperature Adjustment F Furnace Model Factory setting Approximate air temperature change from factory setting 0 20 static on high heat
70. ic transi tion box Remove the plastic caps from the pressure taps on the condensate trap and the plastic transition and connect with the 5 46 OD rubber hose See Figure 43 and Figure 44 Connect the 5 8 OD rubber hose with the 90 bend to the lower 33 NOTE TRAP MUST BE PRIMED BEFORE OPERATION Trap Connection Clamp ears Pointed OUT Return Air into furnace drain stub on the vent fitting and secure with 5 8 clamp Route the hose to the small drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with 5 g clamp NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage 440 08 2002 02 Service Manual Combustion Air Pipe optional Air Intake Some Models have one Pressure Switch Pressure us Vent Pipe i ES Hose Blower Plastic Cap Transition Box Two Stage Multi Position Furnace Horizontal Left Installations Dual Certified 9MPT amp 9MPV A2 Models NOTE TRAP MUST BE PRIMED BEFORE OPERATION Pressure Switch Pressure Switch Blower Transition Supply Air S Yellow Plastic Vent Fitting Clamps
71. icipator to match that value Figure 10 Measuring Current Draw Subbase Ammeter If a low range ammeter is not available a Clamp on type meter may be used as follows 1 Wrap EXACTLY ten 10 turns of wire around the jaws of a clamp on type ammeter 2 Connect one end of the wire to the W terminal of the thermostat sub base and the other to the R termi nal 3 Turn power on and wait approximately 1 minute then read meter 4 Divide meter reading by 10 to obtain correct anticipator setting NOTE For 2 Stage heating thermostats the above proce dure MUST be performed twice Once for first stage W1 and once for second stage W2 if both stages have adjustable heat anticipators If an ammeter is not available a setting of 0 10 amps may be used for models equipped with the HONEYWELL SV9541Q Gas Valve Ignition Control They should howev er provide satisfactory operation in most cases Electronic thermostats do not use a resistance type anticipa tor These thermostats use a microprocessor computer that determines a cycle rate based on a program loaded into it at the factory These cycle rates are normally field adjustable for different types to equipment The method of adjustment however varies from one thermostat manufacturer to another Check with the thermostat manufacturer to find out the proper way of adjusting the cycle rate 440 08 2002 02 Service Manual 12 CONTROL WIRING Control wi
72. ient or Excessive air flow can cause a variety of different operating problems Among these are premature heating component and or compressor failures reduced capacity freezing evapora tor coils etc System air flow should ALWAYS be verified upon comple tion of a new installation or BEFORE a change out heat exchanger replacement or in the case of a compressor failure to insure that the failure was not caused by improp er air flow 440 08 2002 02 24 Two Stage Multi Position Furnace Checking Static Pressure Inclined Indoor Manometer Section CHECKING EXTERNAL STATIC PRESSURE The air flow through the unit can be determined by measur ing the external static pressure of the system and consulting the blower performance data for the particular model furnace you have 1 Setuptomeasure external static pressure at the sup ply and return duct connections See Figure 34 Drill holes in the ducts for pressure taps pitot tubes or other accurate pressure sensing devices Connect these taps to a level inclined manometer or Magnehelic gauge Ensure the coil and filter are clean and all the registers are open Determine the external static pressure with the blower operating Refer to the Air Flow Data for your particular furnace to find the actual airflow for the current speed tap or dip switch setting If the Actual airflow is either too high or too low the blower speed tap or dip switch setting
73. ight side venting from the furnace If the left side venting is required the combustion blower must be relo cated on the plastic transition box Remove the three 4 screws that secure the blower to the transition Rotate the blower 180 and se cure with the three 3 screws Use caution to not over tighten the Screws to prevent stripping out of the plastic mounting holes Plug the upper drain stub on the ventfitting with the rubber plug Use a blunt pointed screwdriver to push the plug into the stub 31 Remove the pressure switch hose from the upper stub on the plastic transition box Relocate the plastic caps on the stubs of the plastic transition box from the lower stubs to the upper stubs and secure tightly with the clamps Route the pressure switch hose to the lower stub on the plastic tran sition box Cut off excess hose and discard Connect the pressure Switch hose to the lower stub on the plastic transition box NOTE Failure to correctly install the pressure switch hose to the transition box can adversely affect the safety control operation Connectthe 3 4 OD rubber hose with the 90 bend to the drain stub on the bottom of the plastic transition box and secure with a 3 4 clamp Route the hose to the large drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with a 3 4 clamp Connect the 9 8 OD rubber hose with the 90 bend to the lower stub on th
74. ill reset and initiate a new ignition sequence 40 Line voltage inputat L1 and Neutral connectors on ST9162A Fan Timer Low voltage 24V power at 24 VAC and COM terminals on ST9162A System wiring harness is in good condition and securely connected Not Applicable Normal Operation stand by or call for heat Pressure switch stuck closed system will wait for pressure Switch to open Pressure switch miswired or jumpered Ignition system control switch must be in the ON position Pressure switch operation tubing and wiring Restrictions in furnace air intake or vent piping Main limit switch Manual reset burner rollout switch Limit and rollout switch wiring is in good condition and se curely connected Flame at pilot burner Gas supply off or pressure too low or high for appliance to operate Damaged or broken HIS element Line voltage HOT lead wire not connected to L1 terminal on ST9162A Furnace not properly earth grounded Flame sense rod contaminated or in incorrect position Pilot burner located in incorrect position Pilot burner lead wires are in good condition and popery con nected Pressure switches operation tubing and wiring Gas supply off or pressure too low or high for appliance to operate Line voltage HOT lead wire not connected to L1 terminal on ST9162A Furnace not properly earth grounded Flame sense rod contaminated or in incorrect position Pilot burner located in incorrect po
75. junction with the SV9541Q GAS VALVE IGNITION CONTROL It provides the power source to begin the ignition sequence through a monitored safety circuit It serves as a low voltage terminal strip and provides accessory terminals for a Humidifier Electronic Air cleaner and a Continuous terminal which can be used on models equipped with a Permeate Split Capacitor P S C motor ONLY to provide continuous fan operation at a speed other than either the heating or cooling speed The control provides a fixed non adjustable 5 second ON and 60 second OFF delay for the circulating blower in COOLING and an adjustable 30 or 60 second ON delay for the circulating blower in HEATING The ST9162A control also provides an adjustable HEAT ING OFF delay for the circulating blower which can be field adjusted to 60 100 140 or 180 seconds Setting and ON delays Setting The ST9162A Heating Fan ON amp OFF Delay is accomplished by the positioning of DIP switches The il lustrations Figure 28 amp Figure 29 indicate how to position these switches to obtain the desired setting 440 08 2002 02 18 Two Stage Multi Position Furnace 20 HONEYWELL ST9162A Series FAN TIMER FURNACE CONTROL Figure 27 Honeywell ST9162A The ST9162A Heating Fan OFF delay can be set to ei ther 60 100 140 or 180 seconds The control was shipped out in the 140 second position This may be satisfactory for some installations
76. lamps Plug the upper drain stub on the vent fitting with the yellow plastic cap Glue the 11 section of PVC pipe to the 90 street elbow after check ing the fit up Follow the procedures outlined in the Joining Pipe and Fittings section of this manual page 30 The PVC pipe will extend through the top panel about 11 2 Connect the rubber coupling to the end of the 11 section of PVC pipe using the clamp Note There will be some misaligment of the PVC pipe inside the fur nace The rubber coupling will straighten out the misalignment at the vent pipe connection at the top of the furnace For left side venting remove 90 street elbow from the vent fitting by loosening the clamp on the vent fitting Securely attach vent fitting to combustion blower NOTE For left side venting the vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope Two Stage Multi Position Furnace This configuration allows left side venting from the furnace If right side venting is required the combustion blower must be relocated on the plastic transition box Remove the four 4 screws that secure the blower to the transition Rotate the blower 180 and secure with the four 4 screws Use caution to notovertighten the screws to pre vent stripping out of the plastic mounting holes NOTE For right side venting the vent fitting MUST be installed with the airflow
77. ly affect the safety control operation Connectthe 3 4 OD rubber hose with the 90 bend to the drain stub on the bottom of the plastic transition box and secure with a 3 4 clamp Route the hose to the large drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with a 3 4 clamp Connect the 9 8 OD rubber hose with the 90 bend to the lower drain stub on the vent fitting and secure with 5 8 clamp Route the hose to the smaller drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with 5 5 clamp NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage Two Stage Multi Position Furnace Figures Downflow Installations Dual Certified 9MPT amp 9MPV Models A1 Models LEFT Side Venting n n a a 4 Return Air Exhaust Combustion Blower Mounting Screws 4 RIGHT Side Venting i Return Air Pressure Switch Transition Lo Fire Pressure Switch Hose Transition Pressure Switch Blower Combustion Blower Rotate 180 for Left Side Rubber Transition Plug Box Plastic Caps Hi Fire Pressure Switch Hose Blower 3 4 Hose Service Man
78. model to obtain the required air flow In all models entire blower assembly slides out on rails for servicing after removing the two screws at the front of the blower deck CHECKING BLOWER MOTOR Variable Speed Models D C Motor The D C Motor used in the variable speed models Cannot 440 08 2002 02 22 Two Stage Multi Position Furnace the difference in size between the flame probe and the burn er ground areathis current flows mostly in one direction This creates a pulsating Direct Current that flows back to the igni tion control proving flame This flame current D C Microamps may be checked while flame is present using a D C Flame Sensor kit is available from outside vendors Permanent Split Capacitor P S C motors are used on the circulating conditioned air blower of 2 Speed models and on the exhaust combustion blower of condensing models Before replacing one of these motors assumed to be bad the condition of its capacitor should be verified since it and not the motor may be the source of the problem Note 9MPT models use PSC motors on circulating blower and on the 125 exhaust blower Before checking any capacitor the supply power to the unit should be turned OFF The capacitor should then be dis charged through a resistor before testing A 20 000 Ohm 2 Watt resistor can be used for this purpose The condition of the capacitor should then be verified with a capacitor analyzer one that indicat
79. move machine screws securing transition drain trap assembly to furnace front partition 5 Remove the collector box 6 Loosen the four 4 screws on the manifold or as an alter native the four 4 screws on the manifold bracket 7 Move the manifold bracket and valve up enough so the secondary heat exchanger will clear the flange on the baffle 8 Remove machine screws securing secondary heat ex changer inlet flange to lower partition 9 Remove screws around perimeter of lower partition 10 Removed screws securing secondary heat exchanger to the supports 11 Coil can now be removed from furnace 12 Reverse procedure to reinstall making sure that any gaskets that have been torn during disassembly are replaced with new ones Primary Heat Exchanger 1 Turn OFF electrical power and gas supply to furnace 2 Disconnect vent pipe to furnace at flexible coupling 440 08 2002 02 38 3 Disconnect combustion air inlet pipe at top panel if needed 4 Remove furnace top panel 5 Disconnect gas piping to furnace at gas valve Note Be fore performing next step insure that the wiring dia gram is available and readable or tag all wires first 6 Disconnect tubing and wiring to pressure switch limit switches and gas valve 7 Remove screws securing burner box to front partition 8 Remove combustion blower 9 Remove machine screws securing transition assembly to furnace partition 10 Remove the collector
80. n Off switch in off position during a call for heat will generate this diagnostic code 4 Flashes Limit switch string open 5 Flashes Flame sensed out of sequence Flame signal still present 6 Flashes 1 Note 1 Soft Lockout Maximum retry count exceeded failed to light within 4 trials for ignition 6 Flashes 2 Notes 1 2 Soft Lockout Maximum recycle count exceeded Last failure was Flame Sense Lost 6 Flashes 3 Notes 1 2 6 Flashes 4 Notes 1 2 7 Flashes 8 Flashes 9 Flashes During Run Cycling Pressure Switch or Blocked Condensate Soft Lockout Maximum recycle count exceeded Last failure was Airflow Proving Circuit Opened During Run Soft Lockout Maximum recycle count exceeded Last failure was Limit Circuit Opened During Run Soft Lockout Due to Limit Trips Taking Longer than 2 minutes to Reset Auto Reset After 1 Hour if Call for Heat Still Present Reset by Cycling Call for Heat at Any Time High Pressure Switch closed when sould be open High Pressure Switch open when sould be closed NOTE 1 The 6 X designation indicates a combination of flash codes 6 flashes shows the control is in soft lockout followed by X flashes to indicate the reason the control went into soft lockout When the 6 X code is flashing the SV9541 will attempt a new ignition sequence after a five minute delay period if the call for heat is still present Reset of the thermostat will initiate a new ignition sequence immediately NOTE 2
81. nge Cooling Airflow 08 800 CFM 12 1200 CFM 14 1400 CFM 16 1600 CFM 20 2000 CFM Cabinet Width 15 5 Wide 19 1 Wide J 22 8 Wide L 24 5 Wide Input Nominal MBTUH Two Stage Multi Position Furnace Service Manual Component Locations for Four Position Furnaces Furnace Vent Pipe Vent Pipe Connection through Side Panel on Some Models Vent Pipe Grommet Manual Gas Valve Rating Plate i Vent Drain Fitting Diagnostic Light Combustion Air Blower 5 8 OD Vent Pipe Drain Hose Condensate Trap g 3 4 OD Transition Box Drain Hose S 1 Door Interlock Switch Fan Delay Control L Primary Heat Exchanger _ Secondary Heat Exchanger Gas Valve Ignition Module Pressure Switches Plastic Transition Box Coils Air Baffle Circulating Air Blower D C Motor Control some models dwg 25 23 29a 3 FURNACE THEORY OF OPERATION The high efficiencies and lower profile compared to previous series ofthis furnace have been obtained using design tech niques not typical of traditional furnace designs A brief de scription of these new design techniques and the purpose they serve follows 1 Reducing the height of the furnace while maintaining the high efficiency of pervious models required work ing the heat exchanger more efficiencly and yet mini mizing the overall si
82. odels in both the Condensing and Non Condensing furnace families The overall operation of all of these models and families is essentially the same with the exception of the Blower Motor and or certain control functions which may be unique to a particular model and or family This manual therefore will deal with all subjects in a general nature all text will pertain to all models unless that sub ject is unique to a particular model or family in which case it will be so indicated Throughout the manual references may be made to VARI ABLE SPEED MODELS as well as TWO SPEED MOD 2 UNIT IDENTIFICATION The unit s rating plate contains important information for the service technician It also lists the complete Model Manufac turing and Serial Numbers These complete numbers are required to obtain correct re Two Stage Multi Position Furnace ELS GENERALLY the distinction between these two groups is based on a difference in the type of Blower Motor used These may not be the only differences however and the differences may vary from model to model within a particular family or series It will be necessary then for you to accurately identify the unit you are servicing so you may be certain of a proper diagnosis and repair See Unit Identification Page 3 A WARNING The information contained in this manual is intended for use by a qualified service technician who is familiar with the safety procedures re
83. of PVC pipe using the clamp NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope Plug the upper drain stub on the vent fitting with the yellow plastic cap Remove the pressure switch hose from the upper stub on the plastic transition box Relocate the plastic caps on the stubs of the plastic transition box from the lower stubs to the upper stubs and secure tightly with the clamps Route the pressure switch hose to the lower stub on the plastic tran sition box Cut off excess hose and discard Connect the pressure Switch hose to the lower stub on the plastic transition box Ensure that the hose is routed above the stub on the transition box so that condensate does not collect in the hose NOTE Failure to correctly installthe pressure switch hose tothe transition can adversely affect the safety control operation Connectthe 3 4 OD rubber hose with the 90 bendto the large drain stub on the condensate trap and secure with a 3 4 clamp Route the hose to the drain stub on the bottom of the plastic transi tion box Cut off excess hose and discard Connect the hose to the drain stub on the transition and secure with a 9 4 clamp Connect the 5 5 OD rubber hose with the 90 bend to the lower drain stub on the vent fitting and secure with a 5 8 clamp 440 08 2002 02 35 Service Manual Route the hose to the smaller drain stub
84. on Air Vent Piping 13 16 Combustion Blower See Exhaust Blower Condensate Drain Trap 17 Control Wiring 11 D Diagnostics 20 21 DIP Switch Settings ST9162A 18 Drain Trap Condensate 17 INDEX E Electrical Supply 4 Electrical Variation SV9541Q 42 Electronic Fan Timer 20 Exhaust Blower 19 External Static Pressure Checking 28 Fan Timer Electronic 18 Flame Current Checking 22 Flash Codes 21 G Gas Valve lgnition Control Honeywell SV9541Q 19 Ground Electrical 4 H Heat Anticipators 9 Heat Exchanger Removal Replacement 38 High Altitude Operation 7 Honeywell ST9162A Fan Timer 18 Honeywell SV9540Q Gas Valve lgnition Control 19 Interlock Switch 5 Introduction 1 L Limit Switches 11 Piping Vent Combustion Air 13 16 Polarity Line Voltage 4 Pressure Switches 12 14 Pressures Approximate Operating 13 R Roll Out Limit Switch 11 Room Thermostat 8 S Sequence of Operation Chart SV9541Q 39 ST9162A Testing Sequence 19 Supply Electrical 4 Supply Gas 5 SV9541G System Operation 20 Switch Blower Door Interlock 5 Switch DIP ST9140 18 Switch Auxiliary Limit 10 Switch LP Gas Pressure 12 Switch Limit 11 INDEX Switch Pressure 12 13 Switch Roll Out Limit 11 T Technical Service Data 44 52 Temperature Rise 8 Testing Sequence ST9162A SV9541Q 21 Thermostat Room 8 Troubleshooting Chart Honeywell SV9541Q 37 38
85. on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with 9 8 clamp Figure 47 DRAIN SIDE VIEW Rotate downward A 20 to 30 LEFT Side Venting S Return Air Pressure Switch Hose Transition Some Models have one pressure switch Combustion Blower 7 4 Pressure Switch Blower Pressure Switch Hose Blower Supply Air NOTE TRAP MUST BE PRIMED BEFORE OPERATION Two Stage Multi Position Furnace NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage Downflow Installations Dual Certified 9MPT amp 9MPV A2 Models RIGHT Side Venting ed js m Return Air Air Intake Combustion Combustion Blower Coupling Air Pipe Option Rotate 180 for Left Side al Yellow Pressure Switch Plastic Cap Transition Transition Box Plastic O Vent Pipe Vent Pipe Grommet Vent Fitting amp Clamps Plastic Caps 3 4 Hose amp Clamps Condensate Trap amp Gas ket Gas Pipe Grommet Drain Line Supply Air 526 Clamp ears
86. one side of the clamp ears on the drain stub through the hole in the casing and push the condensate trap into position Secure with the two screws Reconnect the drain hoses to the stubs on the vent fitting and the plastic transition and secure with the clamps Relocate the plastic caps and clamps on the condensate drain trap from the vertical drain stub to the horizontal drain stubs Secure the clamps tightly to prevent condensate leakage Mount the condensate drain trap in a vertical position to the right side of the furnace using the two screws and gasket that are pro vided Note The condensate trap will be located under the furnace in a vertical position when the furnace is placed horizontally on the right side If needed remove the hole plugs from the furnace side panel and relocated to the open set of holes in the opposite side panel NOTE All gaskets and seals must be in place for sealed combus tion applications Remove the 90 street elbow and vent fitting from the combustion blower by loosening the clamps on the vent fitting Connect the 90 street elbow to the combustion blower using the rubber coupling and clamps Cut a 2 section of PVC pipe from the PVC pipe pro vided with the furnace Glue the 2 section of PVC pipe to the 90 street elbow after checking the fit up Follow the procedures out lined in the Joining Pipe and Fittings section of this manual page 30 Connect the vent fitting to the end ofthe 2 section
87. ons At altitudes over 2 000 above sea level however certain measures need to be taken to in sure continued safe reliable operation For example units must be de rated for altitude by adjusting manifold pres sure and or changing orifice size based upon the type of fuel Natural Gas or L P gas Btu content of the gas and installed altitude 9 BURNERS Burners used in this series of furnace are of the INSHOT type Their operation can be compared to that of a torch in that they produce a hard sharp somewhat noisy flame Noise should not be an issue however because of the closed burner box design In order to insure that the burners are operating properly and attheir design noise level proper adjustment of the gas manifold pressure is essential For further information on manifold pressure adjustments check the section on Gas Supply The burners used in this series ARE NOT EQUIPPED WITH AIR SHUTTERS as none are required Proper operation flame characteristics is obtained by insuring that the orifice size and manifold pressure are correct for the fuel being used and the altitude of the installation Service Manual Figures Typical L P Pressure Switch ALL UNITS must have a high altitude pressure switch installed at altitudes above 4 000 above sea level When servicing a unit installed at altitudes above 2 000 in sure that it has been properly modified to operate at that alti tude See the
88. ow Voltage Terminal Board 115V 60Hz 5 2 Box Low Voltage Terminal Board Ground Two Stage Thermostat Polarity be verified as follows 1 Turn the power supply 2 Using a Voltmeter check for voltage between the Hot Black and Neutral White wire of supply circuit 3 Reading should be Line Supply Voltage 4 Check for Voltage between the Neutral White wire and Ground wire of the supply circuit 5 Reading should be zero Volts if line voltage is read polarity is reversed 6 Azero Volt reading indicates there is no voltage poten tial on Neutral wire 7 Double check by checking for voltage between the Hot Black wire and Ground wire of the supply circuit 8 Reading should be Line supply Voltage if zero volts is read there is no ground or polarity is re versed Two Stage Multi Position Furnace 5 INTERLOCK SWITCH The blower compartment door of all models is equipped with an interlock switch This switch is Normally Open closes when the door is on the furnace and interrupts furnace op eration when the door is open This interlock switch is a safe ty device and SHOULD NEVER BE BY PASSED Since this is a single pole switch breaking only one side of the line proper line voltage is essential to insure that furnace components are not HOT when switch is o
89. pen See Checking Grounding and Polarity 6 GAS SUPPLY Typical Gas Valve Honeywell Manifold Adjustment Hidden ON Diagnostic Light on some models Pilot Adjustment Manifold Pressure Adjustment LO An adequately sized gas supply to the furnace is required for proper operation Gas piping which is undersized will not pro vide sufficient capacity for proper operation Piping should be sized in accordance with accepted industry standards Service Manual Figures Typical Interlock Switch 10 12 96 NATURAL GAS Inlet Supply pressure to the furnace should be checked at the gas valve with ALL OTHER GAS FIRED APPLIANCES OPERATING Inlet Supply pressure to the furnace under these conditions MUST be a minimum of 4 5 W C Water Column If the inlet pressure is less it may be an indication of undersized piping or regulator problems L P GAS Inlet Supply pressure to the furnace should be checked in the same manner as for Natural Gas however with L P Gas the inlet pressure MUST be a minimum of 11 W C If this cannot be obtained problems are indicated in either the reg ulator or pipe sizing Table 1 Gas Pressures Below 2000 Pressure Recommended Wax Win LoFire Natural 7 14 5 5 17 Important Note Supply Pressure With Propane gas the rated input is obtained when the BTU content is 2 500 BTU per cubic foot and manifold pressure set at 10
90. prevent condensate leakage Mountthe condensate drain trap in a vertical position to the left side of the furnace using the two screws and gasket that are provided Note The condensate trap will be located underthe furnace in a ver tical position when the furnace is placed horizontally on the leftside If needed remove the hole plugs from the furnace side panel and relocate to the open set of holes in the opposite side panel Drill two 7 64 diameter holes in the casing using the condensate as the template Ensure thatthe vent fitting and the 90 elbow is securely attached to the combustion blower NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope Plug the upper drain stub on the ventfitting with the rubber plug Use a blunt pointed screwdriver to push the plug into the stub Connectthe 3 4 OD rubber hose with the 90 bend to the drain stub on the bottom of the plastic transition box and secure with a 3 4 clamp Route the hose to the large drain stub on the condensate trap Cut off excess hose and discard Connect the hose to the drain stub on the trap and secure with a 3 4 clamp Connectthe 5 8 OD rubber hose with the 90 bend to the small drain stub on the trap and secure with a 5 8 clamp Route the hose to the lower drain stub on the vent fitting Cut off ex cess hose and discard Connect the hose to the drain st
91. quired in installation and repair and who is equipped with the proper tools and test instruments Installation or repairs made by the unqualified persons can result in hazards subjecting the unqualified person making such repairs to the risk of injury or electrical shock which can be serious or even fatal not only to them but also to persons being served by the equipment If you install or perform service on equipment you must assume responsibility for any bodily injury or property damage which may result to you or others We will not be responsible for any injury or property damage arising from improper installation service and or service procedures placement parts example in certain model families a unit having a MARKET REVISION of C is likely to be equipped with one or more different components MODEL NUMBER IDENTIFICATION GUIDE Brand Identifier T Tempstar N Neture C Comfortmaker Keeprite H Heil Arcoaire X Evaluation Brand Identifier 8 Non Condensing 80 Gas Furnace 9 Condensing 90 Gas Furnace Installation Configuration UP Upflow DN Downflow UH Upflow Horizontal HZ Horizontal DH Downflow Horizontal MP Multiposition Upflow Downflow Horizontal Major Design Feature 1 One Single Pipe 2 Two Pipe D 1or2Pipe 440 08 2002 02 L Low NOx N Single Stage P PVC Vent T Two Stage V Variable Speed Engineering Rev Denotes minor changes Marketing Digit Denotes minor cha
92. r Air Delivery in Cubic Feet per Minute CFM Furnace Rated 0 5 W C ESP Cm 104 wes pw ws m pw pw we pes ew we vs La ps pep pee 5 546 766 60 49 702 889 462 676 833 Always check current Technical Support Manual EXTERNAL STATIC PRESSURE ESP External Static Pressure can best be defined as the pres sure difference drop between the Positive Pressure dis charge and the Negative Pressure intake sides of the blower External Static Pressure is developed by the blower as a result of resistance to airflow Friction in the air distribution system EXTERNAL to the furnace cabinet i e pressure inside duct gt EJ a 20 O u 4 0 0 5 fe o 5 Resistance applied externally to the furnace I E Duct work Coils Humidifiers Filters Etc on either the Supply or Return side of the system causes an INCREASE in Ex ternal Static Pressure accompanied by a REDUCTION in airflow ESP is affected by two 2 factors 1 2 Blower Speed Changing to a higher or lower blower speed tap will raise or lower the External Static Pres sure accordingly Resistance to Airflow as explained above These effects MUST be understood and taken into consid eration when checking ESP Airflow to insure that the sys tem is operating within design conditions Operating a system with Insuffic
93. r test methods Checking from any speed tap lead black orange blue or red to Neutral white should indicate continuity While checking from any motor lead to the motor case should indicate in finity no continuity Before condemning any P S C motor be sure to verify the condition of its capacitor SELECTING BLOWER SPEEDS The wide variety of applications and installations of fur naces throughout the country makes it impossible to Fac tory Select blower speeds that will provide proper opera tion for all installations This means then that the blower speeds for both heating and cooling must be Field Se 23 lected for each particular installation to insure proper op eration The criteria for selecting the proper blower speeds S NOT High for Cooling Low for Heating Although that may be how it works out SOMETIMES It can in many cases be exactly the opposite I E a Lower speed for Cooling and a Higher speed for Heating The PROPER CRITERIA FOR SELECTING BLOWER SPEEDS is as follows HEATING A blower speed must be selected that will provide proper temperature rise through the furnace See checking tem perature rise found on page 9 of this manual The re quired CFM for a particular temperature rise can also be calculated by using the following formula Output BTU Temp Rise X 1 08 CFM EXAMPLE Using a 75 Mbtu Non Condensing furnace equipped with P S C motor of this series with an output of
94. re Range Always check current Technical Support Manual Operate the furnace for 15 minutes before taking tempera ture readings Subtract the return air temperature from the supply air temperature The result is the temperature rise Compare with the allowable rise listed for the model size you are checking Temperature Rise be checked by placing a thermometer in the return air duct within 6 of furnace Place a second ther mometer in the supply duct at lease two 2 ft away from the furnace This will prevent any false readings caused by radi ation from the furnace heat exchanger Make sure that the FILTER IS CLEAN and that ALL REGISTERS AND OR DAMPERS ARE OPEN If the rise is not within the specified range it will be necessary to change the heating blower speed If the rise is too high it will be necessary to increase the blower speed If the rise is too low it will be necessary to reduce the blower speed Example 75 Mbtu 100 Mbtu amp 125 Mbtu Supply Temp 170 Return Temp 70 Temperature Rise 100 Too High Solution Increase Blower Speed An improperly operating or poorly located room thermostat can be the source of perceived equipment problems A care ful check of the thermostat and wiring must be made then to insure that it is not the source of problems Two Stage Multi Position Furnace Thermostat Location THERMOSTAT 5 ft LOCATION The
95. rect part number for the furnace Besides the part number difference the 50M 75M and 100M BTUH models use the shaded pole motor version with the 17 8 diameter back plate with a raised lip The blower gasket is approximately 23 4 outside diameter and is positioned into the recessed opening in the transition The 125M BTUH mod els use the PSC motor version with the 2 diameter back plate with no lip The blower gasket is approximately 31 outside diameter and is positioned on the flat surface ofthe transition A mismatch of blower backplated and or gaskets can cause the furnace to cycle on the pressure switch or to not operate This could be misread as a condensate drainage problem 440 08 2002 02 Service Manual supa Vent Pipe Vent Pipe Grommet LEFT Side Venting Vent Fitting amp Clamps Gas Pipe Grommet Rubber Plug g NS 90 Elbow Rubber Cou i pling 88908 amp Clamps Combustion Blower Plastic Caps Condensat Trap amp Gasket Left or Right Side 4 V 52 amp Clamps Combustion Blower Mounting Screws 4 Drain Line Pressure Switch Transition Lo Fire 25 23 53a Combustion Air Pipe optional Air Intake Coupling Plastic Caps Pressure Switch Hose Blower Pressure Switch Hose Transition
96. ring is an important part of the total equipment installation since it provides the vital communications link between the thermostat and the equipment It is often overlooked as the source of equipment malfunctions Con trol wiring that is either too long undersized or improperly connected be it simply loose or on the wrong terminal can in fact be the source of many equipment problems ALWAYS check to make sure that the control wiring is con nected to the proper terminal s of the equipment and ther mostat you are using Remember also that thermostat terminals are not always identified alike by different ther mostat manufacturers Connections MUST be clean and tight to insure trouble free operation The controls of this series of 2 Stage furnaces are de signed to provide 2 Stage operation using a Two 2 Stage Thermostat ONLY as follows The 2 stage furnace control will operate with either a single stage or a two stage heating thermostat and will provide 2 stage heating operation For single stage thermostat installations the R and W wires from the thermostat connect to the R and W1 connections on the furnace control Note The fourth 4th DIP switch must be in the off position failure to change DIP switch will result in Lo Fire ONLY operation See furnace wiring digram See Furnace Wiring Diagram for switch settings Failure to set DIP switch will result in Lo fire operation ONLY with single stage thermostat During op er
97. sition Pilot burner lead wires are in good condition and properly connected Cycling pressure switch Condensate drain blocked Pressure switches operation tubing and wiring Two Stage Multi Position Furnace Service Manual HONEYWELL SV9541Q SMART VALVE Trouble shooting continued INDICATES CHECK REPAIR LED STATUS 6 Flashes 3 Flashes 6 Flashes 4 Flashes 7 Flashes 8 Flashes 9 Flashes Soft Lockout Last failure was pressure switch Maximum recycle count exceeded Combustion air blower is de energized Circulating blower is de energized after the OFF delay After 5 minute delay time control system will reset and initiate a new ignition seguence Soft Lockout Last failure was limit circuit opened during run Combustion air blower is de energized Circulating blower is de energized after the OFF delay After 5 minute delay time control system will reset and initiate a new ignition seguence Soft Lockout Blower failure typical Limit trip took longer than 2 minutes to reset System will start a new ignition seguence after 1 hour if call for heat still present High Pressure closed when should be open i e when call for heat begins Combustion blower is not energized until pressure switches open High Pressure open when should be closed i e lon gerthan 30 seconds after combustion inducer is ener gized System goes into a 5 minute delay period with com
98. t connections on the fan INCHES OF WATER i Hf board N Note The fourth 4th DIP switch should be in the on position to set the low fire manifold pressure See wir ing digram S AGNEHELIC AX PRESSURE 15 PSIG Repeat steps 4 and 5 for low fire operation N When the manifold pressures are properly set replace the adjustment screw covers on the gas valve 8 Removethe jumper wires from the thermostat connec Typical U Tube tions on the fan board Remove manometer and re Manometer place plug in gas valve 9 Reture fourth 4th DIP switch to previous setting 10 Replace the burner compartment door MANIFOLD PRESSURE AND ORIFICE SIZE FOR HIGH ALTITUDE APPLICATIONS High Altitude Pressure Chart 2000 8000 ft Natural Gas Elevation Above Sea Level DLE 0 1999 2000 2999 3000 3999 4000 4999 5000 5999 6000 6999 7000 7999 3 5 1 7 3 5 1 7 3 5 1 7 3 5 1 7 3 5 1 7 3 5 1 7 3 5 1 7 wesel ee 7 CLOCKING GAS METER NATURAL GAS 5 Operate furnace on LOW fire and time how many se conds it takes the smallest normally 1 cfh dial on the 1 Check with gas supplier to obtain ACTUAL BTU con gas meter to make one complete revolution tent of gas db 6 Calculate LOW fire input rate by using ACTUAL BTU Turn OFF gas supply to ALL other gas appliances content of gas in formula shown in example Operate furnace on HIGH fire and time how many se
99. the clamps tightly to prevent condensate leakage Mount the condensate drain trap in a vertical position to the right side of the furnace using the two screws and gasket that are pro vided Note The condensate trap will be located under the furnace in a vertical position when the furnace is placed horizontally on the right side If needed remove the hole plugs from the furnace side panel and relocated to the open set of holes in the opposite side panel Drill two 7 64 diameter holes in the casing using the conden sate trap as the template Ensure thatthe vent fitting and the 90 elbow is securely attached to the combustion blower NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 downward slope Plug the upper drain stub on the ventfitting with the rubber plug Use a blunt pointed screwdriver to push the plug into the stub Remove the pressure switch hose from the upper stub on the plastic transition box 440 08 2002 02 30 Relocate the plastic caps on the stubs of the plastic transition box from the lower stubs to the upper stubs and secure tightly with the clamps Route the pressure switch hose to the lower stub on the plastic tran sition box Cut off excess hose and discard Connect the pressure Switch hose to the lower stub on the plastic transition box NOTE Failure to correctly install the pressure switch hose to the transition can adverse
100. the clamp on the vent fitting Ensure that the vent fitting is securely attached to the combustion blower using the rubber coupling and clamps This configuration allows left side venting from the furnace If the right side venting is required the combustion blower must be relo cated on the plastic transition box Remove the four 4 screws that 37 Service Manual secure the blower to the transition Rotate the blower 180 and se cure with the four 4 screws Use caution to not over tighten the Screws to prevent stripping out of the plastic mounting holes NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub ata 20 to 30 downward slope Plug the upper drain stub on the vent fitting with the yellow plastic cap Removethe pressure switch hose from the upper stub on the plastic transition box Relocate the plastic caps on the stubs of the plastic transition box from the lower stubs to the upper stubs and secure tightly with the clamps 440 08 2002 02 Service Manual Two Stage Multi Position Furnace 28 HEAT EXCHANGER REMOVAL REPLACEMENT Figure 48 Exploded Parts View Typical Four Position Furnaces 2 38 Secondary Heat Exchanger 1 Turn OFF electrical power and gas supply to furnace 2 Disconnect vent pipe to furnace at flexible coupling 3 Remove combustion blower 4 Re
101. the condensate drain trap from the vertical transition drain stub to the horizontal transition drain stub Secure the clamps tightly to prevent condensate leak age Do not change the cap and clamp on the vent drain stub Mountthe condensate drain trap in a vertical position to the left side of the furnace using the two screws and gasket that are provided Note The condensate trap will be located underthe furnace in a ver tical position when the furnace is placed horizontally on the leftside If needed remove the hole plugs from the furnace side panel and relocate to the open set of holes in the opposite side panel NOTE All gaskets and seals must be in place for sealed combus tion applications Remove the 90 street elbow and vent fitting from the combustion blower by loosening the clamps on the vent fitting Connect the 90 street elbow to the combustion blower using the rubber coupling and clamps Glue the 11 section of PVC pipe to the 90 street elbow after checking the fit up Follow the procedures outlined in the Join 440 08 2002 02 34 ing Pipe and Fittings section ofthis manual page 30 The PVC pipe will extend through the top panel about 11 2 Connect the vent fit ting to the end of the 11 section of PVC pipe using the clamp NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope Plug the upper drain stub on the vent
102. ual Air Intake Coupling Combustion Air Pipe Optional Vent Fitting Vent Pipe Grommet amp Plastic amp Clamps Clamps DRAIN SIDE VIEW j Rotate downward 20 tb 30 5 g Hose amp Condensate a Caps Trap amp Gasket Gas Pipe Grommet Drain Line Supply Air dwg 25 23 56a Downflow Installations Dual Certified 9MPT amp 9MPV Models See Figure 42 Mount the condensate drain trap in a vertical position to either the right or left side ofthe furnace using the two screws and gasketthat are provided If needed remove the hole plugs from the furnace side panel and relocated to the open set of holes in the opposite side panel Drill two 7 64 diameter holes in the casing using the conden sate trap as the template Ensure that the vent fitting is securely attached to the combustion blower using the clamp NOTE The vent fitting MUST be installed with the airflow marking arrow pointed toward the vent pipe with the drain stub at a 20 to 30 downward slope For right side venting remove vent fitting assembly from combus tion blower Remove 90 elbow and rubber tubing from the vent fit ting by loosening the clamp on the vent fitting Securely attach vent fitting directly to combustion blower This configuration allows r
103. ub on the vent fitting and secure with a 9 8 clamp NOTE Ensure hoses maintain a downward slope to the conden sate trap with no kinking or binding for proper condensate drainage 440 08 2002 02 Service Manual Rubber Coupling amp Clamps 90 Elbow 5 g Hose amp Clamps Plastic Caps Vent Fitting amp Rubber Plug Two Stage Multi Position Furnace Horizontal Right Installations Dual Certified 9MPT amp 9MPV 4 MS Combustion Air Pipe Optional Vent Pipe Clamps Combustion Return Blower Air Gas Pipe Grommet Vent Pipe I Combustion Blower Mounting Screws 4 Pressure Switch Hose Transition Pressure Switch Transition Lo Fire NI Grommet Air Intake Coupling 5 O Plastic Caps Condensate Trap amp Gasket Drain Line p di Pressure Switch Blower Hi Fire 3 4 Hose amp Clamps Pressure Switch Hose Blower mu VIEW sv Rotate downward 20 to 30 dwg 25 23 55a Horizontal Right Installations Dual Certified 9MPT amp 9MPV See Figure 41 Relocate the plastic caps and clamps on the condensate drain trap from the vertical drain stub to the horizontal drain stubs Secure
104. ure 13 Pressure Switches Blower Hi fire Transition Lo fire 25 23 72 When servicing a unit whose pressure switch will not close or remain closed during operation the operating pressure of that furnace should be checked and compared to approximate operating pressures listed in Table 3 and the switch setting s listed above for the model family you are servicing It is important to remember that greater negative pressures are created by the furnace when Hot I E upon initial start up than when Cold I E after furnaces has been in opera tion for a few minutes Because of this furnace pressure should ONLY be checked when HOT to insure accurate readings Table 3 lists approximate operating pressures for Direct Vent I E Two Pipe installations of models in this series They were obtained in a test lab under controlled conditions using two 2 specific vent lengths They are included in this manual to provide you with a Barometer to gauge our pres sures against The pressures you obtain in the field will differ slightly from these figures based upon vent length gas pres sure operating temperature etc Major discrepancies in pressures will normally cause problems with pressure switch operation These Major dis crepancies should be investigated as follows Two Stage Multi Position Furnace Service Manual Table 3 APPROXIMATE OPERATING PRESSURES INCHES OF W C Blower Transition High Fire
105. ut Switch Limit Control Setting F Std Pressure Sw Part No 1013515 1013515 1013515 1013166 Blower Switch Pressure Close 0 95 0 95 0 95 1 30 Blower Switch Pressure Open 0 80 0 80 0 80 1 10 Transition Switch Pressure Close 1 70 1 70 1 70 1 80 Transition Switch Pressure Open 1 50 1 50 1 50 1 60 High Altitude Pressure Sw Part No 1013165 1013165 1013165 1013157 Blower Switch Pressure Close 0 70 0 70 0 70 0 85 Blower Switch Pressure Open 0 55 0 55 0 55 0 70 Transition Switch Pressure Close 1 40 1 40 1 40 1 70 Transition Switch Pressure Open 1 20 1 20 1 20 1 50 Blower Data Type amp Size 11 8 11 10 11 10 11 10 Motor Amps Rpm 10 1050 10 1050 10 1050 13 900 Motor Type H p PSC 1 2 PSC 1 2 PSC 1 2 5 Cap Mfd Volts 10 370 10 370 10 370 40 370 Filter Type 16x25x1 16x25x1 16x25x1 16x25x1 2 Cool Cap Tons 5 L ML MHI amp 11 5 2 21 5 3 11 5 2 21 5 3 5 21 5 3 31 5 4 31 2 4 41 2 5 Hi Gas Conversion Kits All Models Nat to LP NAHFOO2LP 1011789 LP to Nat NAHFOO2NG 1011787 Order from Service Parts 440 08 2002 02 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL THIS DATA IS SUBJECT TO CHANGE WITHOUT NOTICE 52 Two Stage Multi Position Furnace Service Manual CIRCULATION AIR BLOWER DATA 9MPT A1 amp A2 For 050 A1 amp A2 Models 3 Ton Units For 075 A1 Models 3 Ton Units Speed Speed SEM ow we Las pe External Static Pressure Inches of
106. vice Manual Two Stage Multi Position Furnace TECHNICAL SERVICE DATA 9MPT A1 amp A2 Specifications 9MPT050F12A 9MPT075F14A 9MPT100J16A 9MPT125L20A 5 Gas Type Transformer Size T stat Heat Input Btuh Std Alt Fire 75 000 100 000 125 000 Lo Fire 53 000 70 000 87 500 Output Btuh Std Alt Hi Fire 69 000 92 000 115 000 Lo Fire 48 800 64 400 80 500 F Hi Fire 40 70 40 70 40 70 Lo Fire 30 60 30 60 30 60 Electrical Volts Hz FLA 115 60 9 8 115 60 9 0 115 60 9 0 115 60 11 2 Gas 8 Ignition Gas Type Nat p Nat Std Main Orifices No Size 2 42 4 42 Gas Valve Honeywell SV 9541 SV 9541 Regulation Type SNAP SNAP Manifold Press Hi Fire WC 3 5 3 5 Lo Fire WC 1 7 17 Pilot Orifice Size 018 018 Ignition Type Series HSP HSP Combustion Flue Outlet Size Inches Std Outlet Temp F Blower Transition Box Hi Fire Std Pressures of WC 5 No Elbows 1 80 2 60 1 80 2 60 1 80 2 60 1 80 2 60 40 5 90 DWV Elbows 1 30 2 30 1 30 2 30 1 70 2 50 1 70 2 50 Blower Transition Box Lo Fire Std Pressures of WC 5 No Elbows 1 20 1 90 1 20 1 90 1 20 1 90 1 30 2 30 40 5 90 DWV Elbows 1 00 1 80 1 00 1 80 1 00 1 80 1 20 2 20 Fan Controls Fan Control Type HW ST9162A Fan Control On 30 60 Timed secs Off 60 100 140 180 Limits amp Controls Rollo
107. z 5438 NI OL AMAA HOLIMS LNOTION EAC HUM 0 8 A MAX COMBINED HEAT ON DELAY 000 1 LAUVONOO JS Arc NAHOJSNVS L AYV Sd S1300W 3WOS MOLIOVdvO 3snd vs HEAT OFF DELAY ku F mH 1234 1234 m 6 SYOLONGNOD 5 H3ddOO L E T 91314 LIOA IH 100 SEC HOLIMS BHnSS3Md 3unss3ud HOLIMS 3NIVA SVO HOLIMS 1 5 NOLLO3NNOO 1 ZHO9 ASL L SM at ONIOIAHAS 340438 LOANNOOSIC LA INVHOVIG NOILOANNOO MOOHS TVOIH O3 13 H39NVG COOL ON DELAY 5 SEC COOL OFF DELAY 60 SEC SETTING Diagram 9MPT A2 5 9 5 5 Wirin 440 08 2002 02 59 ALWAYS CHECK CURRENT TECHENICAL SUPPORT MANUAL Adjusting Heat Anticipator 9 Adjusting Manifold Pressure 6 Air Proving Switch See Pressure Switch B Blower Assembly Conditioned Air 22 Blower Rotation 27 Blower Speeds Changing 25 Blower Speeds Selecting 23 Blower Exhaust 17 Burners 7 C Capacitors 22 Checking Approximate Air Flow 25 Checking Capacitors 22 Checking External Static Pressure 24 Checking Flame Current 22 Checking Grounding 4 Checking Input Firing Rate 5 Checking Manifold Pressure 6 Checking Temperature Rise 8 Combusti
108. ze The design required to achieve these results is the SER PENTINE design wherein the flue gasses must follow a serpent shaped passage through the heat exchanger via convection This Serpentine path is resistive to normal convective flow and requires that a partial vacuum be created at the outlet of the heat exchanger to maintain the flow of flue products through the heat exchanger 2 The serpentine heat exchanger design does not lend itself well to the ribbon type or slotted port type burner found in more traditional design furnaces for the follow ing reasons A The secondary combustion airflows at right angles to the burner flame making it likely to pull the flame off a ribbon or slotted port type burner B The flame height of a ribbon or slotted port type burner would make it difficult if not impossible to prevent im pingement of the flame on the heat exchanger surfaces whole maintaining the low profile heat exchanger For these reasons an INSHOT type burner is used in this series The inshot burner also called a jet burner fires a flame straight out its end This burner is designed to fire into atube style heat exchanger making it an ideal application in the tube like passages of the serpentine heat exchanger 3 In order to extract the maximum amount of heat pos sible from the flue gasses a secondary heat exchang er condenser is connected to the outlet of the primary heat exchanger This condenser r

MULTI POSITION 2-- STAGE GAS FURNACES

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