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Thermo Products MHA1-125N Furnace User Manual

1. ITEM PART NO gt NO R a NO QTY x NO 4 SIDE CASING RIGHT 0117 0117 1 011 0117 5 SIDE CAS LEFT 0116 1 0116 1 0116 6 TOP CENTER PANEI 1 1 8434 1 7 FRONT DOOR 28436 1 28437 28438 8 BLOWER AC 8439 8439 1 8440 1 9 BAFFLE RIGHT SIDE CAS 124 241 1 11241 124 0 DIS BRACKET 18442 1 18442 1 18442 1 18442 BLOWER PAN 18424 3424 1 8425 18426 12 BUTTON PLUG 350045 1 350045 1 350045 3 DOOR PUL 320157 2 320157 2 320157 2 320157 2 14 SIGHT GLASS GASKET 1 330135 15 SICHT GLASS 1 1 15887 1 16 NDUCER 340337 1 340337 17 GASKET 330181 1 1 33018 j 18 FILTER 2 2 370045 2 2 19 BAFFLE LEFT SIDE CASING 8429 1 1 11241 1 124 20 BURNER BOX ASSEMBLY 1 1 1 21 FILTER RACK 24810 1 24810 22 SOR 1 1 1 23 BRACKET HEAT SHIELD 125 11251 125 24 GNITER 380650 25 50054426 1 S0054427 1 1 26 PAN 11250 18427 27 BURNER BOX 11259 11260 1 1 28 LIMIT SWITCH 350913 29 BURNER BOX BOTTOM 1 1 1 30 MANIFOLD 3 VALVE 1 1 1 32 ORIFICE 2 3 5 33 BURNER TUBE 2 3 4 5 34 PRESSURE 35049 1 350491 1 35 LIMIT SWITCH 350495 1 36 DOOR INTERLOCK 1 1 350139 1 5 IARNESS VESTIBULE 550489 1 38 HARNESS SUPPLY 350705 350705 1 39 CONTROL INTEGRATED FAN 1 40 TRANSFORMER 1 350464 1 350464 1 41 IARNESS BI 1 35078 1 42 CAPACITOR 350073 43 MOTOR 1 350346 1 44 MOTOR MOUNT BAND 1
2. Model NO MDA1 50 MDA1 75 MDA1 100 MDA1 125 Heat input rate BTUH 50 000 75 000 100 000 125 000 Heating capacity BTUH 40 000 60 000 81 000 101 000 Nominal temp rise 70 F Heating fan speed LOW MD LOW LOW MD LOW Burner orifice size for nat gas 0 0935 42 Burner orifice size for L P gas 0 0591 1 5 mm AFUE 81 0 80 0 81 0 81 0 Height of casing 44 1 4 Width of casing 17 17 17 17 Depth of casing 27 2 Warm air outlet 15 x 18 15 x 18 19 x 18 22 x 18 Return air inlet 15 x 18 15 x 18 19 x 18 22 x 18 Approx shipping weight 131 LBS 143 LBS 170 LBS 186 LBS Dia of flue vertical vent 3 4 4 4 Dia of flue sidewall vent 3 4 4 4 CFM 2 amp 5 W C external gt 5 gt 5 gt 5 2 5 static pressure HI speed 900 730 1400 1220 1595 1370 2075 1790 MH speed 835 680 1200 1075 1460 1260 1830 1605 ML speed i 926 850 1360 1170 1620 1430 LO speed 580 425 765 700 1220 1075 1345 1265 Blower motor type amp frame Permanent split capacitor air over 48 Y Blower motor nominal HP 1 5 1 3 1 2 3 4 Blower motor full load amps 3 25 6 0 8 0 11 0 Motor shaft diameter L Direction of rotation shaft end Clockwise No of speeds 3 4 4 4 Run capacitor 10 mfd 10 mfd 10 mfd 15 mfd 370 VAC 370 VAC 370 VAC
3. ae NOTE MHA1 50 75 100 125 ST MDA1 50 100 TRANSFORMER USE LOW SPEED FOR HEATING TERMINAL COOLING SPEED HUMIDIFIER EAC _ MDA1 75 125 PARK TERMINALS FOR UNUSED TERMINAL HEATING SPEED USE MED LOW SPEED FOR HEATING SPEEDS MHA MDA1 50 HAS A 3 SPEED MOTOR Figure 8 Blower and Control Panel The option switches on the W R integrated control are used to determine the length of the heat delay to fan on and delay to fan off periods The following tables show the time periods that will result from the various switch positions 28 All installations and services must be performed by qualified service personnel Table 6 Blower delay settings for heating cycles To delay fan Set Switch turn on by 1 2 15 sec Off Off 30 sec Off On 45 sec On Off 60 sec On On To delay fan Set Switch turn off by 3 4 60 sec On On 90 sec Off On 120 sec On Off 180 sec Off Off Factory settings for optimal performance lll Initial Operation of the Furnace A Initial Startup AAWARNING e Turn off power to furnace Before the gas piping system is placed into service it must have been leak tested by a qualified heating contractor Refer to the General Gas Piping Requirements section of this manual regarding the installation and leak testing of gas piping e For initial start up of the appliance after installation it may be necessary to purge the air out of the gas line
4. Burner Feet of Pipe From Meter to Burner Sead AG 20 30 40 50 50 000 1 2 1 2 3 4 3 4 3 4 100 000 3 4 3 4 3 4 3 4 1 150 000 3 4 1 1 1 1 1 4 200 000 1 1 1 1 4 1 1 4 1 1 4 250 000 1 1 1 1 4 1 1 4 1 1 4 300 000 1 1 1 1 4 1 1 4 1 1 4 All black pipe sizes shown are nominal iron pipe sizes Use black iron steel pipe and malleable iron fittings for natural gas service lines Provide rigid supports for the pipe If the pipe size must be reduced use reducing couplings when possible Avoid the use of reducing bushings Remove all burrs and inspect the pipe for dirt or other foreign material prior to connecting Maximum supply pressure for natural gas is 14 0 in W C and minimum supply for purpose of input adjustment is 4 5 in W C 2 INSTALLATION OF PROPANE GAS PIPING WARNING e Copper and brass tubing and fittings except tin lined shall not be used if the gas contains more than a trace 0 3 grains per 100 cubic ft of hydrogen sulfide gas Check with your gas supplier Maximum supply pressure for propane gas is 14 0 in W C and the minimum supply for purpose of input adjustment is 11 0 in W C Experience has proven that the pressure drop in the gas line running from the outside propane gas tank to the gas appliances in a home is the most frequent cause of equipment malfunctions A single pressure regulator located at the tank will not reliably regulate the high tank pressures up to 200 PSIG down to
5. A plenum angles kit AOPS4942 is available for connecting the supply plenum to the furnace The kit consists of four angles that are to be screwed to into the predrilled holes in the base of the furnace using 8 screws The horizontal furnace installation should be on a service platform large enough to allow for proper clearances on all sides and service access to the front of the furnace refer to Table 1 If the furnace is suspended it must be supported at both ends and in the middle with clearance allowed for removal of both access doors Line contact is only permissible between lines formed by the intersection of the top and two sides of the furnaces casing and the building joists studs or framing Equipment must be installed in accordance with regulations of the Supp National Board of Fire Underwriters and the National Fuel Gas GAS SL Code Authorities having jurisdiction should be consulted before installations are made Figure 2 MDA1 Installed Horizontal All installations and services must be performed by qualified service personnel G Duct Work and Air Conditioning Design and installation of the duct system should follow the current guidelines of the Air Conditioning Contractors of America ACCA or the American Society of Heating Refrigeration and Air Conditioning Engineers Inc ASHRAE All furnaces are tested over a range of external static pressure that simulates the airflow resistance of the ductwork f
6. APPENDIX G MID EFFICENCY FURNACE SPECIFICATIONS MID EFFICIENCY HIGHBOY GAS FURNACE SPECIFICATIONS Model NO MHA1 50 MHA1 75 MHA1 100 MHA1 125 Heat input rate BTUH 50 000 75 000 100 000 125 000 Heating capacity BTUH 40 000 59 000 79 000 99 000 Nominal temp rise 70 F Heating fan speed LOW LOW LOW LOW Burner orifice size for nat gas 0 0935 42 Burner orifice size for L P gas 0 0591 1 5 mm AFUE 80 0 80 0 80 0 80 0 Height of casing 44 114 Width of casing 17 17 21 24 Depth of casing 27 2 Warm air outlet 15 x 18 15 x 18 19 x 18 22 x 18 Return air inlet 25 x 16 25 x 16 25 x 16 25 x 16 Approx shipping weight 131 LBS 143 LBS 170 LBS 186 LBS Dia of flue vertical vent 3 4 4 4 Dia of flue sidewall vent 3 4 4 4 CFM 2 amp 5 W C external gt 5 gt 5 o 5 2 p static pressure HI speed 950 830 1495 1335 1795 1560 2245 1970 MH speed 860 740 1205 1125 1590 1410 1885 1710 ML speed i 920 865 1410 1290 1605 1510 LO speed 580 440 750 700 1240 1160 1350 1300 Blower motor type amp frame Permanent split capacitor air over 48 Y Blower motor nominal HP 1 5 1 3 1 2 3 4 Blower motor full load amps 3 25 6 0 8 0 11 0 Motor shaft diameter VA D
7. NOTICE All controls on the unit should be checked for proper functioning prior to the qualified service personnel leaving the job site Specifically the following should be checked 1 With heating system in normal heating operation check to make certain blower will start and stop automatically under control of integrated furnace control 2 Check safety limit control as follows a Shut off incoming power b Block return air opening or disconnect blower motor leads c Restore power to appliance d In the heating mode set the thermostat above room temperature producing a call for heat e When high air temperatures are reached within the furnace the high limit control should act to shutdown the main burners f Shut off the electrical power IMPORTANT Remove blockage or reconnect blower motor and restore power 3 Make certain the thermostat will automatically start and stop the appliance 4 Block the vent terminal outlet gradually with a flat piece of metal until the pressure switch functions shutting off the main burners IMPORTANT Remove flue blockage when done NOTICE Heat exchanger oil will burn off on initial firing creating an unpleasant odor To prevent this odor from occurring more than once it is suggested the furnace be allowed to run for 30 minutes or until odor has dissipated 36 All installations and services must be performed by qualified service personnel IV Troubleshooting NO
8. l us D HUM N hT OPTIONAL T aaa 5 S EAC N L ELECTRONIC AIR YY E w MRN CLEANER 24v ef D TR N gt TT x YELLOW Ni FAN ON DELAY 45 SEC vow FAN OFF DELAY 180 SEC DU 07 DIOLO y O S OHH ODA USED ON UDA RED EFS R ee WRG6CO G S SSI M K AUX LIMIT E out pees ee IE 1 SL I o o OPTIONAL WRT A C CONTACTOR ars HTG COOL THERMOSTAT g E L J T x E SF P S N H IGNITOR ae RED PRESS SW YELLOW EES last BROWN BROWN L J BROWN ae e Z HIGH LIMIT C A FLAME ee L SENSOR vy BLUE G f G LL La ROLL OUT MV BLUE LIMIT RED SAP ORANGE O_o E S 1 CONNECT HOT TO L1 AND COMMON TO N DIAGNOSTICS L PRESSURE SWITCH N 0 1 FLASH SYSTEM LOCKOUT 21 9 IF ANY OF THE ORGINAL WIRES AS 2 FLASHES PRESSURE SWITCH STUCK CLOSED oS DEW ie RISE SUPPLIED WITH THE FURNACE MUST 3 FLASHES PRESSURE SWITCH STUCK OPEN L l i BE RREPLACED IT MUST BE l 4 FLASHES OPEN LIMIT SWITCH E T7 CHASSIS GROUND REPLACED WITH WIRING MATERIAL HAVING A 6 FLASHES 115 VOLT AC POWER REVERSED C TEMPERATURE RATING OF AT LEAST 105 C 7 FLASHES LOW FLAW SIGNA Bleis ae DES ice oe GROUND Hi e EARTH GROUND 3 SET HEAT ANTICIPATOR AT 0 8 AMP ee ae ba D CONTINUOUS FLASH FLAME SENSED WHEN NO FIELD WIRING 4 MDA1 MHA1 50 HAVE A 3 SPEED MOTOR FLAME SHOULD BE PRESENT MDA1 75 AND MDA1 125 WIRED FOR MD CONTINUOUS ON INTERNAL CONTROL FAILURE ui LOW SPEED FOR HTG FACTORI WIRING 54 All installat
9. 1 45 MOTOR MOUNT L 3 350819 3 3 46 BL S0054143 47 AUX LIMIT 1 424 1 48 BUTTON PLUG 350060 350060 350060 1 350060 49 CASING BACK 18430 18430 18431 18432 50 PLENUM STRIP 13382 Z 13382 2 3382 2 13382 2 5 w 52 LP CONVERSION KIT 4 AOPS 53 VENT CHUTE K AOPS4941 AOPS4941 1 AOPS gt OPTIONAL KITS NOT SHOWN 54 PLENUM ANGLE KIT AOPS4942 1 AOPS4942 1 1 53 All installations and services must be performed by qualified service personnel APPENDIX F WIRING DIAGRAM WD S47 A ECN 4283 MA WIRING DIAGRAM Ne MHA1 50 75 100 125 lt W A E TRS ee MDA1 50 75 100 125 s aT DOOR j BLOWER MOTOR L Back AMOH BLACK S C WHITE 7 BLACK HIGH RED LOW a EN BLUE MD LOW YELLOW MD_ HICH Jf WHITE COMMO a A BLACK S F GREEN OcOOL H PARK PARK LINE O O elu es S i w 77 HEAT H HH W HUW H A OPTIONAL WHITE HUMIDIFIER RANSFORMER 50A65 145 m LINE N
10. JHL 902 ALIY 1Y SINNSSY LNAWdINOA SIHL JO J9NYLd300Y AG YISYHOYNd IHL ANY GND ANY JO JDVAIVG LNINOISNOO HOS ALNIAYIT ON SINNSSY 971 SLONGOYd OWYSHL HINNYN ANY NI ALNYHJYM SIHL 20 SWH3L SHL AJICOWN YO Y317Y OL ALIHOHLNY SVH NOSN2d ON 971 SLONGOYd OWYSHL JO SNOILY980 ANY SSILNVYYVM Y3HLO 11V 3Q3SH44dNS AISSIHdXI ALNYHYYYM SIHL JAOgY d3LS1 SJILNYHYYYM 11V ANY ANY GIOA TIIM SNOILIGNOD JA09Y 40 ANY HLIM A1dWIO9 OL 3401Y POS JO Sjoe Jo pue eGewwep 1616 0 anp anje Aue 104 ajqisuodsal aq jou eys O71 S oNposg oway ssalppe uonejezsu jeuiBuo s ye upewa zsnw yun aul l QOBUIN BU JO Apis 1e Lune y UO paesu aq Aew ioo dund yeey Jo Buluolipuos we ON H uorjesnBiyuoo UBIsap sy uey Jeyjo Jauuew Aue uj peyeiedo Jo pue paljipolw aq you snw yun 34L 9 pessed Aq Jo naeg peljlpoww aq jou snwW swnwxew yes e1d BulAey pue pun au UMA pal ddns ase yojym sjoJuoo yw 4 aanre JeBueYoxe yeay 0 Hulpes Aaw seoejins JOUU y JO UOIJeIOLa Ep pide asneo aveuuny e Jo ease uonsnqwioo y BuLajue USU yorym dnos6 uaBojey y jo Aue Jo euLONy 10 euojyo Aq payeujuezuoo uo s alaydsoUye SAlso0d y UO JeoI dde sedoud Buluseou0d 977 sjonpold OEY BuyoLuoo ysuy noun sBuip ing eLysnpul Jo suojes jneaq syewoupune s uewusiiqeyse Bujueajo Ap ul punoj aq Aew se yons siena aseydsouje 3AS01109 e sey eunjonyjs Aue U p j ezsu q you ysnw yun eul 2 SUO ONJSUI uonjesedo pue uoNeE eISUl 9711 SLONGONd OWYSHL 10 pu
11. MDA1 100 MDA1 125 THERMO 254 402 PERMANENT FILTER pm me ome e Ea Es DISPOSABLE TYPE FILTER The Thermo Products supplied filter can be cut to size to fit other filter retention systems as long as the minimum size requirement is met PRODUCTS 172 328 208 394 344 56 SUPPLIED Ea STANDARD PERMANENT 500 FILTER NOTICE The filter areas in Table 2 are the minimum areas required based on the flowrate generated by the furnace for standard heating speeds only The following formula can be used to determine the minimum filter area required for cooling if the unit is equipped with cooling This value should then be compared to the value shown in table 2 and the larger of the two should then be used for determining the minimum filter area required for that installation FORMULA tons of cooling 400 CFM per ton 144 sq in per foot filter area sq inches max air velocity of filter from table 5 for the filter type EXAMPLE If you had an MHA1 MDA1 100 furnace and 4 tons of cooling and a standard reusable filter 4 tons x 400 CFM x 144 460 square inches for cooling 500 For heating an MHA MDA 100 needs 328 square inches of standard reusable filter The filter system must be designed for the larger flow requirement determined for cooling of 460 square inches A filter would have to be sized so that the area length x width was at least 460 sq in All installations and services must be performed by qualified se
12. Pia SUPPLY AIR Pe MDA1 SERIES Figure 11 Filter Location FILTER REPLACEMENT Should the filter used require replacement see Table 2 in Section Il of this manual for minimum filter areas required for the different types of filters available to ensure an adequate replacement is selected 40 All installations and services must be performed by qualified service personnel IMPORTANT Remind homeowner of the importance of monthly filter inspections during operation to ensure maximum efficiency VI Installers Instructions to User After completing the installation the installer shall inform and or demonstrate to the homeowner 1 The location of these instructions in the furnace and that these instructions and the users information manual must be kept along with instructions for any accessories in the plastic pouch on the inside of the furnace 2 The location and use of the manual gas shut off valve and furnace electrical disconnect switch Instruct user to always shut off gas before shutting off electric power 3 The sequence of operation of the furnace 4 The correct operation and maintenance of the appliance as outlined in the users information manual 5 That failure to maintain and operate this furnace in accordance with these instructions could result in hazardous conditions bodily injury and property damage and may void the limited warranty on the furnace 6 Review with and encourage the user to r
13. above in Table 5 25 All installations and services must be performed by qualified service personnel M Electrical 1 Wiring AAWARNING The furnace must be grounded in accordance with local codes or in the absence of local codes with the National Electrical Code ANSI NFPA 70 2002 or latest edition All wiring shall be performed by a qualified electrician or service person The wiring must comply with local codes the instructions in this manual and in the absence of codes with the National Electrical Code ANSI NFPA 70 or latest edition Follow these guidelines to complete the wiring portion of the installations A separate power supply circuit with over current protection and a disconnect switch must be provided The minimum fuse or circuit breaker size is 15 amp All electrical components and junction boxes shall be installed in such that they are protected from water All MHA1 MDA1 series furnaces are supplied with a switch box to be mounted on the outside surface of the right or left side casing A strain relief bushing is provided for support of the supply wire harness Make the 115 volt supply connection in this junction box A green screw is provided in order to connect the power supply ground wire A disconnect switch can be field mounted on the 2x4 box provided If not the disconnect switch must be located reasonably close to and within sight of the furnace NOTICE The hot surface igniter and operation of this f
14. box assembly can be removed from the separator panel by removing the screws behind the 1 holes near the top of the burner box and the one screw in the flange under the burner box 4 Inducer Blower Assembly Inspect pressure switch tubing connections and inspect inducer blower assembly for corrosion warpage deterioration and carbon build up If necessary clean housing and blower wheel with a damp cloth Vacuum to remove any lint or dust from motor assembly The inducer gasket and the collector box gasket must be replaced if they show any sign of having been damaged 5 Clean all furnace markings as necessary and verify that all are still legible Any illegible or missing markings must be replaced Replacements can be obtained by contacting Thermo Products Once all components are cleaned they must be re installed to their factory produced state Any seals or joints in the flue system which have been removed or loosened must be reconnected and sealed if necessary Do this in accordance with the installation instructions Section Il J of this manual for vertically vented units or Section II K of this manual for sidewall vented units NOTICE After cleaning the furnace reference the burner adjustment section of this manual Check for operation proper combustion and no gas leakage according to the procedure outlined in Section Ill of this manual Burner and Adjustment Observe the burner flame illustrations and follow the adjus
15. so that it is centralized with respect to the duct system Place the unit so that proper venting can be achieved with a minimum number of elbows in accord with the instructions in this manual The furnace should be located as close to the chimney vertical venting or to the outside vent wall horizontal venting as practical The furnace must be located on a level dry surface in an area which is free from and protected from excessive drafts The furnace must be installed so that the electrical components are protected from water If the area becomes wet or damp at times the furnace should be raised above the floor using a concrete base bricks patio blocks etc When installing this furnace provisions must be made to insure the supply of adequate combustion and ventilation air in accordance with the air for combustion and ventilation section of the National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or latest edition or applicable provisions of the local building code See Section II E of this manual A furnace installed in a residential garage must be installed so the burners and ignition source are located 18 inches or higher above the floor Also the furnace must be located or protected to avoid physical damage by vehicles If this furnace is to be installed horizontally see Section Il F of this manual C Closet and Alcove Installation All furnace models may be installed in a closet or alcove on combustible flooring with sp
16. uodo sy 19 PIAA IIM 977 S ONpold OEY sAOsjap SeUuOdEq JeBueyoxe yeay y ponad AjUeLeM y Buunp 161 uoneesu Joye sad y ua 24 PUCA q StU AUS ye 4 Aueue awya papu e SeLueo seBUeYoXe yeay euL AVIA HLOL AHL GNOAAG juawipedeq BOIMOS Igoiuuoa l 977 sJoNpold oway aly Aq p yu a q zenu suoppuoo peyUBIEM Japun ang JeBueYyoxs esy y JO Uopepiea Wed Jo SOeUINY auioaie p 24 Jo UOWISodsip uo Jal eap y 0 Suononaysu YM 4414 predeid Aq paddiys aq IW sped eda Jo JaBueYyoXe yeay soeUINy jUeLUeoR del pajueem ey 1009 Aessaoau y 104 9169p Y AH peylyenb peroidde ue yym aBueue Kew saumo eUl JEUMO y JO Ajliqisuodsel y ale JeBUeYOXe ze y 10 SOBWINY OU Jo JUSWIEORIde1 pue eAcWAL BU 10 JedeJ sisouBeIp y Ul PaA OAU S SO9 0091 AU siseq aBseyo ou e uo sped edau Aessasau y 10 JeaBUeYOXe yeay jUEWadR del e Jsenbal S Jajeep BHullje sul 2y e 10 soeuny jUeLUsoe da ajqeseduoo e sprod M 977 SJONpol OEY aAljoajap s wos q Jebueyoxe ze y y uoyejjezsu 194e 129 UU yno TS 94 BuUnp ow Aue ye 4 Aueue 2wa poyu e Soleo JaGueyox yeoy OU HI NYHOXI LVAH YYIA HLOL LSL 09909 SI JaBUEYOXA yeay eoeUNy y juo eat yyy ay PUCANG Ped aioaiep Jo Uosods p UO Jajeap aui 0 SUOHONJSU UIA 1U Dia pledeid Aq peddiys aq Ilm sped yueweoedes pajueep aumo y Jo Ayiqisuodse y ese ped eAnoajep e Jo 1ueuueogide pue jeaowa SU 10 99S sisouBelp soeuiny Ul paout S s09 Joge AUy ped anoaja
17. usually be improved by filling the base of the chimney with sand to within 12 of the flue pipe after relocating the cleanout cover All joints of the vent must be tightly sealed The inside of the vent should be free of all obstructions 2 Replacing An Existing Furnace From a Common Vent WARNING CARBON MONOXIDE POISONING HAZARD Failure to follow the steps outlined below for each appliance connected to the venting system being placed into operation could result in carbon monoxide poisoning or death When an existing furnace is replaced or removed from a common vent serving other appliances the vent system may now be too large to properly vent the remaining appliances only and must be modified accordingly Failure to correct an oversized vent can cause the formation of condensate leakage or spillage of combustion byproducts which may cause property damage personal injury or loss of life The steps below must be followed with each appliance which is still connected to the common venting system Each appliance should be placed in operation while the other appliances remaining connected to the common venting system are not in operation 1 Seal any unused opening s in the common venting system 2 Visually inspect the venting system for proper size and horizontal pitch as required in the National Fuel Gas Code NFPA 54 ANSI 2223 1 2002 or the latest edition Determine there is no blockage or 13 All installations and
18. 11 0 in W C Varying pressures will occur at the appliances as outside temperatures and usage demands vary Two stage regulation is the only effective method of controlling gas pressure refer Figure 7 24 All installations and services must be performed by qualified service personnel FIRST STAG l aa l REGULATION P GAS E SECOND STAGE E E ANK l ULATOR L VA St A Ba ie A Pn ar sg ae R ITI S A HIHHH H H HIH HH eea 18 l C S ST E A FET ET FE YPICAL 2 STAGI p Figure 7 Typical Piping For Two Stage Regulation NOTICE Two stage regulation must be installed for propane gas when used with any Thermo Pride propane furnace See illustration above of a typical two stage piping system Table 5 COPPER TUBING SIZE FOR PROPANE GASES E COPPER 1 2 0 D COPPER All black pipe sizes shown are nominal iron pipe sizes Seamless copper tubing may only be used with gases that are not corrosive to it See note below and check with your LP gas supplier before using Seamless copper tubing must comply with standard type K or L for seamless copper water tube ASTM B 88 or seamless copper tube for air conditioning field service ASTM B 280 Copper tubing sizes for indicated BTU input rates are given
19. 14 1 10114 10114 6 OP CENTER PANEL 18410 18410 1 18411 18412 FRONT DOOR 18404 8 BLOWE 28400 9 DOOR PULI 320157 2 2 2 2 2 340337 340337 3 4 FILTER 5 BURNER BOX ASSEMBLY 6 DIS BRACKET 18442 18442 1 18442 18442 7 BAFFLE BLOWER PAN 18362 18443 1 11249 8 BAFFLE REAR CASING 11247 9 BAFFLE LEFT SIDE CASING 18417 11241 1 11241 11241 20 SENSOR 350759 21 GNITER 22 PARTS PACKAGE 23 BURNER BOX 24 MIT oH 25 BURNER BOX BOTTOM 15831 5830 26 MANIFOLD 27 28 ORIFICE 2 3 4 5 29 BURNER TUBE 2 3 4 5 30 PRESSUR 350491 31 LIMIT SWITCH 32 DOOR INTERLOC 3 HARNESS VESTIBULE 34 HARNESS SUPPLY 350704 35 CONTROL INTEGRATED FAN 36 RANSFORMER 39 MOTOR 40 MOTOR MOUNT BAND 4 MOTOR MOUNT LEG 3 3 3 3 42 LOWER S00S4143 43 BAFFLE RIGHT SIDE CASING 18416 ERZ 1 11241 11241 44 NG BACK 18407 18407 1 18408 18409 45 PLENUM STRIP 13382 2 13382 2 2 13382 2 8 LP CONVERSION K 1 AOPS7664 1 All installations and services must be performed by qualified service personnel REPLACEMENT PARTS LIST MDA1 lit f LLLL C P J lilit 52 All installations and services must be performed by qualified service personnel MDA1 MDA1 100N MDA1 125N
20. 440 VAC Blower size 10 9 RDD 10 9 R DD 10 10 R DD 10 10 RDD Size of filters 2 1 xX 17 x 2 1 x 17 x 2 1 x 17 x 2 1 x 17 11 11 13 x 17 Largest recommended aud 2 Ton 3 Ton 3 5 Ton 4 Ton conditioner Electrical power requirements 115 volts 60 Hz 1 phase Min Fuse size 15 AMP 15 AMP 15 AMP 20 AMP ACCESSORY ITEMS Combustible Floor Base 50DA BASE 50DA BASE 100CA BASE 125CA BASE Horizontal Plenum Angles AOPS4942 Vent Kit top vent option AOPS4941 NOTES 1 BTU output based on annual fuel utilization efficiency rated by manufacturer 2 On all outlet and inlet dimensions the first dimension is width 3 The MHA1 MDA 1 furnaces are approved for sidewall venting using only an approved sidewall power venter Refer to Side Wall Venting section of the nstallation and service manual provided with the furnace for additional information 4 To permit largest recommended air conditioning at 5 static pressure selection of the highest motor speed is required 5 All specifications are subject to change without notice 57 S ES at Ee ES Sea eS RSS a ne nae r See diz ayes AUD ON BLES ON SPO Ssalppy uoneesu uopejesu JO 3ed elaun diz ayes MO 12 968 7LS Hd ss lppy g9 9y euepu j uospnf YLON We xog 0 d SUURN siajeeq 971 s onpold OSU SHJHLO NO JSAOTdWS SIH HISYHOYNd IHL AP ISNSIN YO ASN SLI 40 JONINOISNOO
21. A qualified heating contractor should do this If excessive gas escapes when purging the gas supply at a pipe union joint allow the gas to disperse for at least 15 minutes before attempting to start the appliance LP gases are especially dangerous because the specific gravity of LP gases allows them to accumulate at ground level at possibly explosive concentrations Review the following items before the initial startup It may be helpful to review the Sequence of Operations in Appendix B of this manual also a Check all wiring for loose connections and proper hook up Refer to the connection diagram 29 All installations and services must be performed by qualified service personnel b Leak test all field gas piping connections c Check the tubing to the pressure switch to make sure it is snug and completely seated on the pressure tap d Check to see that the vent terminal is correctly installed and the terminal openings are clear and free from blockage e Make sure the air filter is in place and relatively clean of dirt and debris f Make sure the thermostat is set in the heating mode of operation For Your Safety Read Before Operating A WARNING If you do not follow these instructions exactly a fire or explosion may result causing property damage personal injury or loss of life This appliance does not have a pilot light It is equipped with a hot surface igniter that automatically lights the burner Do not attempt
22. B 875 350750 1 INSTALLATION PARTS PACKAGE MHA1 MDA1 75 S00S4427 MDA1 MHA1 100 S00S4428 MDA1 MHA1 125 S00S4429 DESCRIPTION PART NUMBER QTY WIRE NUT 300132 2 8X1 2 TEK SCREWS 300208 2 for mounting 2X4 J box 10 32X1 2 GND SCREW 300109 1 10 32 HEX NUT 300110 1 3 16 DIA STAR WASHER 300270 1 2X4 J BOX 350024 1 2X4 J BOX COVER 350020 1 GROUNDING INSTRUCTIONS MG 966 1 HEYCO SR 34 2 350016 1 HEYCO UB 875 350750 1 3 X 4 TAPERED TRANSITION 14310 1 49 All installations and services must be performed by qualified service personnel REPLACEMENT PARTS LIST MHA1 APPENDIX E 2 BLOWER WS ASSEMBLY ef 7 7 di 50 All installations and services must be performed by qualified service personnel UNITS MHA1 50 MHAT 75N MHA1 100N MHA1 125N TEM SE S PART NO aly PART NO Qty PART NO ary PART NO QTY 1 HEAT EXCHANGER 3841 2 BLOWER ASSEMBLY S004129 S0054131 3 BAS 18395 18395 18397 4 SIDE CASING RIGHT 10115 10115 1 10115 10115 5 SIDE CASING LEFT 10114 101
23. ELBOW sg z z ao MDA1 50 MDA1 79 100 125 Figure 4 Vent Connection to Inducer A self tapping sheet metal screw and high temperature sealant such as Dow Corning 736 or General Electric RTV106 temperature rating 480 F minimum should be used to secure both the flue pipe MHA1 MDA1 50 and the Thermo Products supplied 4 in adapter MHA1 MDA1 75 MHA1 MDA1 100 MHA1 MDA1 125 to the outlet of the inducer If using other than a self tapping sheet metal screw to secure the flue pipe to the inducer a starter hole must be drilled in the inducer before inserting the screw refer to Figure 4 to avoid damage to the inducer housing 17 All installations and services must be performed by qualified service personnel When venting the MDA1 series through the blower compartment a vent chute AOPS4941 must be used Refer to Figure 4 This option requires the removal of the two 4 inch diameter plastic plug from the blower pan and the top panel of the unit After removing the plastic plugs run the 3 inch diameter vent through the vent chute and the top and bottom openings The MDA1 75 MDA1 100 and MDA1 125 will require the use of the 3 inch to 4 inch adapter provided This adapter is to be installed after the 3 inch vent exits the furnace The 3 inch diameter vent running through the vent chute must be a continuous section No connections should be within the vent chute If this venting option is not utilized the 4 inch diameter plastic plu
24. TICE BEFORE TROUBLESHOOTING FAMILIARIZE YOURSELF WITH THE START UP AND CHECKOUT PROCEDURE ALL INSTALLATION AND SERVICES MUST BE PERFORMED BY QUALIFIED HEATING CONTRACTORS To assist you in troubleshooting this furnace it is equipped with an integrated ignition control with diagnostics These diagnostics evaluate what control system has experienced a failure and activate a flashing light on the control in different sequences to help pinpoint the failure which has occurred Also provided in appendix C is a troubleshooting flow chart located in the back of this manual IMPORTANT For your convenience Thermo Products has installed a sight glass in the blower door of this furnace The number of flashes in groups should be observed through this sight glass and recorded before turning off power to the furnace Otherwise power to the furnace will be interrupted upon or removing the blower turning off power or removing the necessary to restart the furnace and have the failure occur again DIAGNOSTIC FEATURES The 50A65 control used on this furnace continuously monitors its operation and the operation of the system If a failure occurs the LED light on the control will failure code If the failure is internal to the control the light will stay on continuously In this case the entire control should be replaced as the control is not field repairable If the sensed failure is in the system external to the control the LED will flash in the foll
25. Thermo Pride Bra INDUCED DRAFT HIGHBOY AND COUNTERFLOW HORIZONTAL GAS FURNACE INSTALLATION AND SERVICE MANUAL MODELS MHA1 50N MDA1 50N MHA1 75N MDA1 75N MHA1 100N MDA1 100N MHA1 125N MDA1 125N A WARNING IF YOU DO NOT FOLLOW THE SAFETY PRECAUTIONS BELOW AND IN THIS MANUAL A FIRE OR EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE PERSONAL INJURY OR LOSS OF LIFE DO NOT STORE OR USE GASOLINE OR OTHER FLAMMABLE VAPORS AND LIQUIDS IN THE VICINITY OF THIS OR ANY OTHER APPLIANCE WHAT TO DO IF YOU SMELL GAS DO NOT TRY TO LIGHT ANY APPLIANCE DO NOT TOUCH ANY ELECTRICAL SWITCH DO NOT USE ANY PHONE IN YOUR BUILDING LEAVE THE BUILDING IMMEDIATELY IMMEDIATELY CALL YOUR GAS SUPPLIER FROM A NEIGHBOR S PHONE FOLLOW THE GAS SUPPLIER S INSTRUCTIONS e IF YOU CANNOT REACH YOUR GAS SUPPLIER CALL THE FIRE DEPARTMENT INSTALLATION AND SERVICE MUST BE PERFORMED BY A QUALIFIED INSTALLER SERVICE AGENCY OR THE GAS SUPPLIER REFERRED TO IN THESE INSTRUCTIONS AS A QUALIFIED HEATING CONTRACTOR PLEASE READ THESE INSTRUCTIONS PRIOR TO INSTALLATION INITIAL FIRING AND BEFORE PERFORMING ANY SERVICE OR MAINTENANCE THESE INSTRUCTIONS MUST BE LEFT WITH THE HOMEOWNER AND SHOULD BE RETAINED FOR FUTURE REFERENCE BY QUALIFIED SERVICE PERSONNEL THERMO PRODUCTS LLC BOX 217 MG 1008 NORTH JUDSON IN 46366 ECN 4283 MA PHONE 574 896 2133 MADE IN USA Contents SECTION Notice TOME WIS CAE D 2 aps ae Ss Eaa Zd vedio GeuwsdeuSs s a
26. ashing Yes If LED Light Flashes 1 Flash then pause System lockout 2 Flashes then pause Pressure switch stuck closed 3 Flashes then pause Pressure switch stuck open 4 Flashes then pause Open high limit aux limit or roll out switch 6 Flashes then pause 115 Volt AC power reversed 7 Flashes then pause Low flame sense signal 8 Flashes then pause Check ignitor or improper grounding Continuous flashing Flame has been sensed when no flame no pause should be present no call for heat Does burner shut off No Check for short in wire to when thermostat is thermostat Replace satisfied thermostat if necessary Does the circulating air Check DIP switch settings blower turn off after on ignition control module thermostat is satisfied against those on connection within 180 seconds diagram Reset if necessary Troubleshooting Complete 48 All installations and services must be performed by qualified service personnel APPENDIX D PARTS PACKAGE COMPONENTS INSTALLATION PARTS PACKAGE MDA1 MHA1 50 S00S4426 DESCRIPTION PART NUMBER QTY WIRE NUT 300132 2 8X1 2 TEK SCREWS 300208 2 for mounting 2X4 J box 10 32X1 2 GND SCREW 300109 1 10 32 HEX NUT 300110 1 3 16 DIA STAR WASHER 300270 1 2X4 J BOX 350024 1 2X4 J BOX COVER 350020 1 GROUNDING INSTRUCTIONS MG 966 1 HEYCO SR 34 2 350016 1 HEYCO U
27. d cubic foot of the fuel gas supplied to the appliance at the installation site If the higher heating values are unavailable it is reasonable to assume values of 1025 BTU cu ft for natural gas or 2500 BTU cu ft for commercial propane gas 2 With all other gas consuming appliances turned off and using a stopwatch clock the time required for the small dial on the gas meter to make one full revolution The meter dial will indicate how many cubic feet pass through the meter during one revolution usually one two or five The unit must have been in operation at least 15 minutes before clocking 32 All installations and services must be performed by qualified service personnel 3 The following formula may be used to calculate the heat input rate for the appliance Gas heating value x Amount of gas consumed_ Heat input rate or Amount of time required to consume the gas BTU cu ft x Number of cu ft x 3600 seconds Input rate BTU hr Seconds for one revolution x 1 hour In cases where a gas meter is not installed on the fuel gas supply line the input rate can be assumed to be approximately correct if the burner manifold pressure is the same as that shown on the rating label Make sure the gas supply pressure at the appliance falls within the allowable range for the type of fuel gas See table 8 The pressure to the furnace must be checked while the burner and any other gas appliances on the same supply system are operating Mea
28. during the cycle of the furnace the moisture may accumulate in large enough quantities to cause problems such as corrosion of the chimney or corrosion of the furnace heat exchanger This condensation most likely will not occur at the bottom of the chimney because the flue gas is heating the chimney walls as it rises and the bottom will be heated first This heating of the walls will cause the flue gas temperature to drop which in turn may reduce the wall temperature below the dew point causing condensation to appear on the upper part of the chimney first This condensation may drip back as far as the flue pipe and heat exchanger where corrosion may occur if not corrected To prevent condensation it is necessary that the internal chimney wall temperature always be kept above the dew point The chimney may have to be lined with a flue liner if the temperature loss is too great for the furnace A liner will act as an insulator and reduce the flue gas temperature loss Insulation may be added around the liner for further temperature stability If the chimney is on the exterior of the home and condensing occurs the chimney may be insulated around its exterior to help the flue hold it s temperature Also check to see if the chimney is too large for the flue gases to heat if so reduce to proper size by lining Be sure to use steel liners such as stainless types 430 304 316 or for the toughest against corrosion type 29 4C More detailed informatio
29. e sapos ajeys pue 18201 ym souepsoo e u pauezujew pue dn jes palje sul eq snw pun aul A s epoo Bunu a Ansnpul uano yym aouepIoooe Ul peuBlsap w S sS Ju A e pue SUOI EPUSLULUODA uonipa uano q jenueyy eonawy Jo s10 921 Uu00 Bujuoppuog Jy YOO ym aouepioooe UL pauBisep was s np e Uy asado enu yun 34L O pauBlsap Sem y YOIUAA JO N y UIA pad pue aqel Bunel y uo payeoipul se Ajyjoedeo payed sy UIUJIM pasado aq snu yun aul g J9 LaP y 0 pjos sem yun y ayep y 1 ye kep u06 UJeHeUTU pasepisuos aq jm uonejesu Jo ajep au poued Aep 06 Ajoutu y aye pauma JOU S GUYO NOILYYLSIOJY ALNYHHYAM pajejduioo y 4 abeJaao9 juene M SyeN Oe 0 uonerezsu Jo sep 06 AJSUIU uym CYVO NOILYHLSI JY ALNVYYWM y unja pue zejdwuo9 pinoys saumo SUL Y YY ALNYVHYYM SIHL 40 SNOLLIGNOO SHL JQUMO BU Jo su dxX y Je uopepodsue1 predad Aq peuunia ad snu y EAA yua y Jaye JBBUEYOXE Jey 3A09J P Oy JO UNJ aU S S Nb 1 977 sjonpold ouu y J aumo y Jo Ayjiqisuodsay y aje sped edau y 10 JaBUeYOXe ze y aja dLUOS y Jo JUaWEORIdal y YM paeroosse s soo uopepodsue y Aue Jea U1US1 y puoheg Joqe Aless9oau aul 104 Jajeap OWAH payljenb Aue yym aBueve Aew saumo y aumo dU Jo Ajliqisuodse y are JeBUeYOXe ze y e Jo 1ueujeogid e pue PAOLA y 10 Ieda sIsouBeIp y Ul paAjOAUl s S09 Joge Auy siseq e6yeyo ou e uo sped ieda Alesseoau y Jo JeBUeYOXe Jey zjuaw oejd e Jaye
30. ead the warnings and instructions outlined on the front cover and the Safety section of this manual and in the Users Information Manual 7 Recommend to the user that a CO detector be installed in the living space with the use of any fossil fuel burning appliance The CO Detector should be one that is design certified by a nationally recognized testing agency 8 Recommend that the user have a qualified heating contractor inspect the furnace at the start of each heating season Inform the user of the frequency of inspection required for each item in Section IV of the Users Manual 9 Inform the user to maintain adequate clearances around air openings into the furnace and not to block or restrict the entrance of air into the furnace area or the furnace air opening 41 All installations and services must be performed by qualified service personnel APPENDIX A SOURCES FOR REFERENCE STANDARDS 1 Air Conditioning Contractors of America 1712 New Hampshire Avenue NW Washington D C 20009 202 483 9370 2 American Gas Association Distribution Center P O Box 79230 Baltimore Maryland 21279 0230 301 617 7819 3 American National Standards Institute Inc Attn Customer Service 11 West 42 Street New York New York 10036 212 642 4900 4 American Society for Testing and Materials 100 Burr Harbor Drive West Conshohoken Pennsylvania 19428 2959 610 832 9585 5 American Society of Heating Refrigeration and Air Condition
31. ecified standard clearances to combustible construction The furnace shall not be installed directly on carpeting tile or other combustible material other than wood flooring The MDA1 50 75 100 and 125 horizontal counterflow furnace models requires an optional combustible surface mounting base for counterflow installation directly on combustible materials The combustible floor base model numbers are as follows 50DA BASE for MDA1 50 All installations and services must be performed by qualified service personnel and MDA1 75 100CA BASE for MDA1 100 and 125CA BASE for MDA1 125 refer to Figure 1 Figure 1 Counter flow Furnace Combustible Surface Mounting Base D Standard Clearances Definitions of combustible material and non combustible as issued by the National Fuel Gas Code are as follows Combustible Material Materials made of or surfaced with wood compressed paper plant fibers plastics or other material that will ignite and burn whether flameproof or not or whether plastered or not plastered Non combustible Material Material which will not ignite and burn such materials consisting entirely of steel iron brick concrete slate glass plaster or combination thereof Table 1 Minimum Clearances to Combustible Materials Sides amp Rear Front of Top of Sides of Model No of Furnace Furnace Plenum Flue or Vent Plenum in in in in in Covered by 1 6 1 This Manual 6 in clearance may be reduced to 1
32. ending on a number of factors A few of these factors are changes in the actual resistance of the duct system to airflow at any time de rating of the appliance due to elevation fouling of the heat exchanger surfaces and changes in the fuel gas heating value In general a lower temperature rise through the heating section will result in higher heating efficiency Temperature rise supply air temperature return air temperature After 15 to 20 minutes of continuous operation the temperature rise through the furnace must fall within a range of 55 to 85 F If the outlet or supply duct temperature is too high check to make sure the return air filter is clean the return air registers are free from obstruction the outlet registers are properly adjusted and clear and the supply and return air ducts are open The circulating air blower is not moving enough air if the supply air temperature is still too high Before proceeding further turn off the power supply to the appliance and remove the blower access door The speed of the blower must be increased by changing the speed tap from the motor to the next higher tap refer to Figure 8 35 All installations and services must be performed by qualified service personnel E Checkout Procedure Before any system of gas piping is finally put into service it shall be carefully tested to assure that it is gas tight as indicated in the General Gas Piping Requirements section of this manual
33. esponsibility to inform and demonstrate to the user the correct operation and maintenance of the appliances explained in this manual the user s information manual and the sidewall vent manufacturer s manual 1 Horizontal Size and Lengths for Horizontal Vents The minimum sidewall vent length is two 2 feet of straight vent pipe with one 1 elbow and one 1 adapter or transition to inducer The maximum vent length and permitted number of elbows are shown in the following table Table 3 Horizontal Size and Length for Sidewall Venting ang Max Length of Vent EQUIVALENT MODEL NUMBER Pipe in Feet With LENGTH OF FURNACE VENT OF VENT T ELBOWS MHA1 MDA1 50 MHA1 MDA1 75 MHA1 MDA1 100 MHA1 MDA1 125 Each elbow used is considered to be equivalent to 5 feet of straight vent pipe 20 All installations and services must be performed by qualified service personnel L GAS PIPING GENERAL GAS PIPING WARNING FIRE OR EXPLOSION HAZARD Failure to follow the safety warnings exactly could result in serious injury death or property damage Never test for gas leaks with an open flame Use a commercially available soap solution made specifically for the detection of leaks to check all connections Because of the potential of odorant fade a gas leak may not be detected by smell If this furnace is installed below grade contact your gas supplier for a gas detector All gas piping must be leak tested using a soap and water s
34. essure drop C Burner Adjustment There are no manual adjustments to the main burners With the burner compartment door removed the flames can be observed Natural gas flames should be relatively short in length have well defined shapes and are bright light to deep blue in color refer to Figure 10 NOTICE For appliance operation with propane gas it is not unusual to observe mostly blue flames having yellow or yellow orange tips 34 All installations and services must be performed by qualified service personnel BURNER Figure 10 Typical Observation of Main Burner Flames If long rather poorly defined mostly yellow in color and nearly opaque burner flames are observed this is an indication the quality of combustion is poor Under adverse conditions black smoke and some sooting may be noticeable as well Some of the causes of poor combustion are too high an input rate over firing too little or a contaminated supply of combustion air or a partially blocked heat exchanger or vent terminal Should any of these conditions occur they must be corrected immediately Call your qualified heating contractor for assistance D Setting Supply Air Temperature Rise All MHA1 MDA1models are designed and wired at the factory for a blower speed during heating that should result in an approximate temperature rise of 70 F The temperature rise through the heating section for any given blower speed may vary dep
35. f the appliance as explained in the Users Information Manual Inform the user of the hazards of flammable liquids and vapors and to remove such liquids and vapors from the vicinity of the appliance Inform the user of warnings and cautions as well as user information in the sidewall venting manufacturer s manual when sidewall venting is applied Il Installation Guidelines A Codes All local codes and or regulations take precedence over the instructions in this manual and should be followed accordingly In the absence of local codes installation must conform to the instructions and the regulations of the National Fire Protection Association National Electrical Code ANSI NFPA70 2002 and the National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or the latest editions thereof The heating capacity of the furnace proposed for installation should be based on a rate of heat loss calculation made according to the manuals provided by the Air Conditioning Contractors of America ACCA or ASHRAE All installations and services must be performed by qualified service personnel B Installation Location WARNING e These furnaces are designed for indoor installation only These furnaces are NOT to be used as construction heaters e The return air duct of the furnace must be sealed air tight to prevent starvation of the combustion air especially if the furnace is located in a closet or confined area For best performance locate the furnace
36. fold gas pressure e To adjust the pressure remove the brass screw from the regulator on the outlet side of the gas control valve Using a common screwdriver increase the manifold pressure by turning the screw inward clockwise or decrease it by turning the screw outward counterclockwise Adjustments to the listed pressure must not exceed 0 3 in W G A 0 3 in W G adjustment will change the input approximately 4 0 f Measure the heat input rate by counting the number of seconds required for the appliance to consume a specified quantity of gas Refer to the preceding procedure to calculate the heat input rate g If required repeat the manifold pressure adjustment again Repeat the input rate measurement h When the input rate adjustment has been completed shut off the fuel gas to the appliance Remove the pressure gage Reinstall the manifold pipe plug using a thread compound resistant to the action of LP gases Replace the regulator screw cap in the gas valve If an input rate within the allowable range cannot be obtained with the present orifice over the range of manifold pressures given make sure the gas supply pressure is within the specified range If the supply pressure is less than required the upstream supply pressure regulator may have to be adjusted to increase the pressure If increasing the gas supply pressure fails to provide adequate gas pressure at the unit the supply piping may have to be modified to reduce pr
37. g in the blower pan and the 3 1 2 inch diameter plastic plug in the top panel of the unit should be left in place for proper furnace operation The flue may exit the unit through the top left side or right side of the unit refer to Figure 5 The inducer can be rotated by removing the four 4 inducer mounting screws and rotating the inducer housing Ensure that inducer gasket is in place before reinstalling inducer l N INDUCER MOUNTING basse at SCREWS 4 PLACES T o f e INDUCER WITH GASKET INDUCER ASSEMBLY INDUCER ASSEMBLY ORIENTATION FOR ORIENTATION FOR LEFT SIDE VENT RIGHT SIDE VENT Figure 5 Inducer Mounting All vent connectors connecting the furnace to the vent must be rigidly supported with hangers and straps in order to prevent sagging and movement after installation The vent connector must be supported at a maximum of every four feet depending on the design and weight of the material used to maintain clearances and to prevent physical damage The vent pipe must slope upward a minimum of 1 4 for each foot of horizontal run away from the furnace Vent connectors used in connecting the furnace to the vent cannot be channeled through floors ceilings and walls without the proper protective construction This construction must be in accordance with the requirements of the National Fuel Gas Code NFPA 54 ANSI 2223 1 2002
38. g the amount of flue gas that is introduced to it The vent must be vertical or nearly vertical in design unless equipped with a UL listed mechanical venter This furnace must not be connected into any portion of a mechanical draft system operating under a positive pressure This furnace shall not be vented into an unlined masonry or concrete chimney PVC piping is not an acceptable substitute for a chimney or a flue connector A chimney with an internal construction of stainless steel or some other material that will withstand a gross flue gas temperature of 480 F is required 12 All installations and services must be performed by qualified service personnel These venting tables also include venting combinations which apply to common venting arrangements of two or more appliances These requirements as well as all the installation requirements outlined in this manual for an MHA1 MDA 1 series furnace must be followed when an MHA1 MDA1 furnace is common vented with another Category gas appliance See also Section Il J 2 of this manual Replacing an Existing Furnace From a Common Vent for information on testing the proper operation of appliances in a common vent The minimum allowable chimney height is determined by the height of the surrounding trees roof buildings and terrain The chimney should extend 24 above any surrounding obstructions In cases where the chimney flue extends to the basement floor the draft can
39. gnitor terminals IGN amp IGN N at the ignition control module Yes Check wiring to hot surface ignitor If okay replace hot surface ignitor assembly Check across MV terminals on ignition control module for 24 VAC during the 4 second flame proving period after ignitor warm up Is there 24 VAC Yes Check wiring to gas valve If okay Replace gas valve 46 No Check the ignition control module diagnostic LED lamp Reset the module by interrupting power to system for more than one second If LED stays on continuously replace ignition control module All installations and services must be performed by qualified service personnel After gas valve opens do the burners ignite Do burners stay lit past proof of flame check Yes Measure gas supply pressure No at inlet to gas valve Is it at No least 4 5 W G for natural gas or 11 W G for L P gases Check gas supply Open all manual gas control valves serving the unit Yes Check ignitor voltage during 20 second warm up No it should be A least 105 Correct low line voltage VAC problem or replace ignition control module Yes P ia No bi Is ignitor positioned Reposition to correctly correct location Check for blocked or severely corroded burners or burner orifices Clean or replace as required Adjust supply pressure to 4 5 W G for
40. in with UL Recognized type B1 vent The minimum clearances are listed for fire protection Clearances for servicing and proper operation the front of the furnaces and to all points on the furnace requiring access must be 24 in All installations and services must be performed by qualified service personnel E Air for Combustion and Ventilation A CAUTION Relief openings in the front or top of the furnace casing should not be obstructed or blocked These openings supply combustion and ventilation air to the furnace Chloride fluoride iodide and bromide bearing compounds when present even in low concentrations in air supplied for combustion to the furnace can result in accelerated and severe corrosion of the heat exchanger and or the venting systems This condition can occur with less efficient furnaces but is accelerated on furnaces with efficiencies of 80 or greater Many household chemicals contain chloride bearing compounds There are many compounds representative of this classification of chemicals A few common examples are listed below Cleaning solvents Varnish and paint removers Bleaches Fabric softeners Water softener salt Tile adhesives Avoid installing the furnace in areas where it is evident these chemicals are being stored or used within close proximity to the furnace In addition avoid storing or using any chemicals of an unknown nature in close proximity to the furnace If it is necessary to store or
41. ing Engineers Inc 1791 Tullie Circle N E Atlanta Georgia 30329 404 636 8400 6 National Fire Protection Association 1 Batterymarch Park Quincy Massachusetts 02269 800 344 3555 42 All installations and services must be performed by qualified service personnel APPENDIX B SEQUENCE OF OPERATIONS A Sequence of Operations for Heating System Mode of Operation Standby At any time the gas valve is not energized Start Start trial for ignition Control System Action Continous safe operation check If flame simulation condition present or roll out switch opens system energizes inducer fan and circulator blower at high speed until situation correction occurs Thermostat calls for heat contacts close Ignition control module energized draft inducer starts Pressure switch senses adequate pressure contacts close Power is applied to the hot surface ignitor Ignitor warms up for 20 seconds On power interruption system shuts off restarts when power is restored After ignitor warm up the automatic gas control valve is energized to open If flame is not detected the gas valve is de energized the ignitor is turned off and the ignition control module goes into the Retry sequence Flame must be detected within 4 seconds If flame detected the delay to fan on time begins 45 seconds The retry sequence provides a 60 second wait before ignition re
42. ing that each appliance remaining connected to the common venting system is venting properly when tested as outlined above and the vent system is properly sized Common vent sizing of two Category appliances may be done as referenced in the National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or the latest edition thereof 3 Condensing in the Chimney Due to the improved designs resulting in increasing thermal efficiencies of our furnaces more heat is being placed into the home instead of up the chimney This means the stack temperature will be lowered which may result in All installations and services must be performed by qualified service personnel condensing within the chimney under certain conditions The following is an explanation on why and what to do if condensing occurs in a chimney or vent Moisture in the form of water vapor occurs in flue gases when hydrogen is combined with oxygen during the chemical reaction produced by combustion The flue gas water vapor will do one of two things as it escapes up the chimney 1 Remain in a vapor state if the internal chimney wall temperature is above the dew point or 2 Condense on the chimney walls if they are chilled below the dew point Condensing will always occur on chimney walls whose temperatures are below the dew point of the flue gas However the water may evaporate once the walls are warmer than the dew point If the chimney walls do not reach the dew point
43. ions and services must be performed by qualified service personnel EMPERATURE SWITCH OPEN ON TEMP RISE WD 546 ve RADIAN A ECN 4283 MA WIRING DIAGRAM LADDER L HI 7E N MHA1 50 75 100 125 ADA E F E oe MDA1 50 75 100 125 WITCH W 50465 143 INTEGRATED CONTROL Je p2 00T power eagle MOTOR e we BC2 pose I p ee FAC H BC me HUM H DI IC 2 a u ND H INDUCER kl N ic WA 6 MAA N IGN IG LL NITRIDE IGNITER 115V AAAA 50465 143 e S TH voy V g 3 AMP 24 V CAS VALVE IS E C M Bc PS PRESSURE SWITCH see HLI HLO o ToO G O L r ih HEATING HICH ROLL OUT AUX LMT V USED ON MDA COOLING LIMIT MODELS ONLY THERMOSTAT m FLAME SENSOR TR CND thi o o AAAS I PRESSURE SWITCH N O 1 CONNECT HOT TO L1 AND COMMON TO N oco 7 T 2 IF ANY OF THE ORGINAL WIRES AS SUPPLIED WITH THE FURNACE E MUST BE REPLACED IT MUST BE REPLACED WITH WIRING MATERIAL G 77 CHASSIS GROUND HAVING A TEMPURATURE RATING OF AT LEAST 105 C FARTH GRO 3 SET HEAT ANTICIPATOR AT 0 8 AMP D 4 Gia 4 MDA1 MHA1 50 HAVE A 3 SPEED MOTOR BC BLOWER CONTROL W R 50A65 143 MDA1 75 AND MDA1 125 WIRED FOR MD LOW SPEED FOR HIG ic IGNITIO CONTROL W R 50A65 143 55 All installations and services must be performed by qualified service personnel
44. irection of rotation shaft end Clockwise No of speeds 3 4 4 4 Run capacitor 10 mfd 10 mfd 10 mfd 15 mfd 370 VAC 370 VAC 370 VAC 440 VAC Blower size 10 7 RDD 10 9 RDD 10 9 R DD 10 9 R DD Size of filters 1 1 x 24 x 1 1 x 24 x 1 1 x 24 x 1 1 x 24 15 15 15 x 19 Patgest recommended air 2 Ton 3 5 Ton 4 Ton 5 Ton conditioner Electrical power requirements 115 volts 60 Hz 1 phase Min Fuse size 15 AMP 15 AMP 15 AMP 20 AMP ACCESSORY ITEMS Filter Rack AOPS 7547 AOPS 7547 AOPS 7547 AOPS 7375 Flange dimensions 24 1 2 X 15 24 1 2 X 15 24 1 2 X 15 24 X 19 NOTES 1 BTU output based on annual fuel utilization efficiency rated by manufacturer 2 On all outlet and inlet dimensions the first dimension is width 3 The MHA1 MDA 1 furnaces are approved for sidewall venting using only an approved sidewall power venter Refer to Side Wall Venting section of the Installation and service manual provided with the furnace for additional information 4 To permit largest recommended air conditioning at 5 static pressure selection of the highest motor speed is required 5 All specifications are subject to change without notice 56 All installations and services must be performed by qualified service personnel MID EFFICIENCY COUNTERFLOW HORIZONTAL GAS FURNACE SPECIFICATIONS
45. ittings and diffusers connected to the furnace for a typical average duct system The furnace blower and blower motor have been selected to work successfully against the following range of duct system resistance Recommended range of duct system resistance for all models 0 2 to 0 5 in W G external static pressure When the furnace is installed in a small room and no return air ducts are used the return openings to the unit should extend full size to a location outside the furnace room If the furnace is used in connection with summer air conditioning cooling the air conditioner s evaporator coil must be installed on the air outlet side of the furnace to avoid water vapor condensation in the furnace heat exchanger NOTICE Return air grilles and supply registers in the air distribution system should not be obstructed H Filters Filter Installation Filters must be installed external to the furnace casing It is necessary to cut the return air opening in one or both side s of the MHA1 models depending upon the needs of the specific installation This MHA furnace has been factory supplied with a high quality re usable filter rated for air velocities up to 600 ft min An optional Thermo Products filter rack assembly part no AOPS7547 for MHAS5O 75 100 and AOPS7375 for the MHA125 is available which is sized for the filter provided If an optional Thermo Pride filter rack Figure 3 is used with the furnace square knock
46. l valve can be manually operated Rotate the gas control valve knob or switch lever to the OFF position Wait five 5 minutes to clear out any gas Then smell for gas near the ground If you smell gas STOP Follow section h in the safety information above If you don t smell gas go to the next step Rotate the gas control valve knob or switch lever to the ON position Replace the burner compartment cover Turn on the electric power to the appliance Set the thermostat to the desired setting If the appliance will not operate follow the instructions To Turn Off Gas To Appliance and call your service technician or gas supplier To Turn Off Gas To Appliance Set the thermostat to the lowest setting and set the operating mode switch to OFF If service is to be performed turn off the electrical power to the appliance To turn off the gas control valve remove the burner compartment cover Rotate the gas control valve knob or switch lever to the OFF position Replace the burner compartment cover 31 All installations and services must be performed by qualified service personnel B Adjustment Of Heat Input Rate The main burner gas orifices for this unit were selected based upon the following assumed characteristic values of the two fuel gases suitable for use with this appliance design a For natural gas having a higher heating value of 1025 BTU per standard cubic foot and a specific g
47. n on condensing may be obtained from the 2000 ASHRAE systems and Equipment Handbook Chapter 30 Refer to National Fuel Gas Code NFPA 54 ANSI Z2223 1 2002 or latest edition Category venting tables for proper vent sizing 15 All installations and services must be performed by qualified service personnel 4 Flue Vent Connector Z WARNING s Either drill a starter hole in the inducer or use a self tapping screw to mount the flue pipe to the inducer Failure to follow these instructions may damage the inducer e All vents and vent connectors must fit tightly to avoid air leaks s The MHA1 MDA 1 series furnaces must not be installed with vent damper The connection of this furnace to the vent system shall be in accordance with the local building codes the vent manufacturers instructions and part 10 Venting of Equipment of the National Fuel Gas Code NFPA 54 ANSI 2223 1 2002 or latest edition These venting tables also include venting combinations which apply to common venting arrangements of two or more appliances These requirements as well as all the installation requirements outlined in this manual for an MHA1 MDA 1 series furnace must be followed when an MHA1 MDA1 furnace is common vented with another Category gas appliance See also Section Il J 2 of this manual Replacing an Existing Furnace from a Common Vent for information on testing the proper operation of appliances in a common vent The vent co
48. nace refer to Fig 6 If local codes permit the use of a flexible gas appliance connector always use a new listed connector Do not use a connector which has previously served another gas appliance 22 All installations and services must be performed by qualified service personnel STREET ELBOW GAS VALVE 44 N P T MANIFOLD PRESSURE TAP 1 INSTALLATION OF NATURAL GAS PIPING The installation of the gas piping and the following test procedures must be m GROUND JOINT MANUAL GAS SHUT OFF VALVE MHA1 SERIES SEDIMENT TRAP NOTE ACTUAL UNIT MAY DIFFER SLIGHTLY FROM WHAT IS SHOWN Figure 6 Typical Gas Piping performed by a qualified installer or service person The following chart may be used as a guide in sizing natural gas supply piping The input loading of all gas appliances installed on any main or trunk line must be totaled to determine its required carrying capacity EXAMPLE A line must supply a furnace of 100 000 BTU hr input a hot water heater of 40 000 BTU hr input and gas range with a 30 000 BTU hr input capacity The total BTU hr input loading on the line is 170 000 BTU hr The 200 000 BTU hr column on the chart must be used in sizing the pipe All installations and services must be performed by qualified service personnel TABLE 4 Steel Pipe Size for Natural Gas IPS
49. natural amp 11 No Measure supply amp manifold Wao for LP gases Adjust pressures Are they constant over time and within the allowable ranges Check DIP switch settings on ignition control module against Does the ignition control module energize the circulating air blower after the 45 second time delay those on connection diagram Is blower still inoperable after time delay with DIP switches set correctly Yes Measure voltage on the circulating air blower terminals CIR N amp HEAT Is it 120 VAC Does the circulating air fan come on when energized Does blower wheel spin freely Is blower motor capacitor working properly Yes Replace Motor 47 manifold pressure to 3 5 W G for natural gas or 10 W G for LP gases If gas pressure fluctuates a pressure regulator may be required or gas piping may be too small for flow Check wiring to blower If okay replace the ignition control module Check for blower wheel rubbing against housing or motor shaft spinning freely Adjust or replace as necessary Replace blower motor capacitor All installations and services must be performed by qualified service personnel Yes Does system run until y thermostat is satisfied No Is LED light on ignition No Check all wiring for R loose connections control module fl
50. ng is 0 8 AMPS for furnace operation only To increase length of the heating cycles increase setting of heat scale to decrease length of cycle decrease setting of heat scale Anticipators for the heating operation are of two types pre set and adjustable Those that are pre set will not have an adjustment scale and are generally marked accordingly 27 All installations and services must be performed by qualified service personnel Anticipators for the cooling operation are generally pre set by the thermostat manufacturer and require no adjustment 5 Blower Motor Speed Wiring ZA WARNING e TURN OFF THE ELECTRICAL POWER to the furnace before attempting to change blower speed wiring The blower motor is factory wired to the ignition control with standard heating and cooling speeds pre selected When changing motor speeds simply switch the wire from the needed speed to either the heating or cooling terminal as applicable on the module to obtain the desired airflow The wires for the unused speeds should then be reconnected to the module in the park positions Pp GREEN CAPACITOR J __ OPTIONAL FAN T a DELAY SWITCHES COMMON WHITE _ MED HIGH SPEED YELLOW ___ MED LOW SPEED BLUE EAC COMMON R LOW SPEED RED HUMIDIFIER COMMON HIGH SPEED BLACK
51. nnector must be galvanized or stainless steel metal pipe and must be a 3 in in diameter for the MHA1 MDA1 50 and 4 in in diameter for the MHA1 MDA1 75 MHA1 MDA1 100 and MHA1 MDA1 125 The MHA1 MDA1 75 MHA1 MDA1 100 and MHA1 MDA1 125 are supplied with a 3 in to 4 in adapter as a transition from the inducer to the 4 in vent size see figure 4 No size reduction is permissible For minimum and maximum vent lengths see Venting Tables for Category appliances in the National Fuel Gas Code NFPA 54 ANSI Z2223 1 2002 or latest edition All installations and services must be performed by qualified service personnel SELF TAPPING SHEET METAL SCREWS T 4 INCH FLUE PIPE S NOR F SERPE Tona ay 3 INCH TO 4 INCH ADAPTER SUPPLIED i WITH UNIT L o z j 0 a T i E E B d a l L Ne ei le n o By X o E aN 6 P MHA1 50 MHA1 75 100 125 ty 4 INCH FLUE PIPE 3INCH FLUE PIPE 3 INCH TO 4 INCH ADAPTER SUPPLIED LL l WITH UNIT l 7 h 7 l Z I y TOP PANEL i TOP PANEL g C a L VENT CHUTE l BLOWER PAN l BLOWER PAN L o ma Ue nape A f o d 1 ii NU a ie N St eo j I a Ne ae A TT _ 2 3 INCH ELBOW gt Bee 3 INCH
52. nstructions for the humidifier or EAC for additional requirements 4 Room Thermostat A room thermostat is not furnished with this furnace However a thermostat is required to properly operate the furnace control system The room thermostat should be located in the natural circulating path of the room air The thermostat should not be placed where exposed to cold air infiltration i e drafts from outside openings such as windows and doors or where exposed to air currents from supply or return air registers or such that natural circulation of air is blocked such as behind doors in shelves or in corners It should always be located on an interior wall In addition the room thermostat should not be exposed to heat from a nearby fireplace electrical appliances lamps rays from the sun or mounted directly on a wall containing warm air ducts a chimney or a gas vent These sources of heat could adversely affect the operation of the thermostat preventing it from properly controlling the room temperature Generally a room thermostat should be set at the lowest temperature that is comfortable to the building occupants This will result in the lowest cost to heat the building Proper control of the indoor temperature can only be achieved if the thermostat is calibrated to the heating and or cooling cycle A vital consideration of this calibration is related to the thermostat heat anticipator The proper thermostat heat anticipator setti
53. o the troubleshooting section of this manual All installations and services must be performed by qualified service personnel APPENDIX C TROUBLESHOOTING FLOWCHARTS A Heating System Set thermostat subbase to HEAT Does thermostat make contact No Yes l Is room temperature Turn thermostat setting above thermostat setting above room temp Is the transformer supplying 24 VAC to the thermostat Replace thermostat y Are the thermostat wires connected Correct wire properly connections No Check input power control system fuse disconnecting switch and fuses if equipped Is the control transformer receiving 120 VAC Yes Replace control transformer U Is there 24 VAC across TH amp TR terminals of the ignition control module Is the inducer blower operating Check for continuity amp proper connections 45 All installations and services must be performed by qualified service personnel Yes After pre purge does the hot surface ignitor energize and glow Yes U After hot surface ignitor warm up does gas valve open Yes Yes Is there 120 VAC across draft inducer power terminals IND amp IND N at the ignition control module Check wiring to draft inducer If okay replace inducer assembly Is there voltage present at the hot surface i
54. o the furnace shall be in accordance with requirements of the local utility Piping from the propane tank to the furnace must follow the recommendations of the gas supplier A readily accessible design certified manual shut off valve with a non displaceable rotor member shall be installed within six feet of the gas equipment it serves A union or flanged connection shall be provided downstream from the manual valve to permit removal of controls A 1 8 N P T plugged tapping is provided at the inlet of the gas control for connection of a test gage to check gas supply pressure to the furnace Unions must be of a ground joint type or flanged jointed using a gasket resistant to LP gas Pipe dope or sealant certified to be resistant to the action of liquefied petroleum gases shall be used on all threaded joints Left and Right Gas Supply Piping This furnace is set up to accept either left or right side gas piping using a street elbow and a straight pipe A sediment trap drip leg must be used on both propane and natural gas installations to trap oil condensate and other impurities which might otherwise lodge in the gas valve or plug the burner orifice The sediment trap shall be installed as close to the furnace inlet as possible When there is excessive condensation between the gas meter and the furnace a sediment trap shall be provided at the outlet of the gas meter Failure to install a sediment trap may void the limited warranty on the fur
55. of A qualified installer also referred to in this instruction manual as a qualified heating contractor is an individual or agency that is responsible for the installation and adjustment of the equipment A qualified installer is properly licensed and experienced to install gas burning equipment in accordance with all local codes and ordinances Any reference to L P or propane gas in this manual any other label or markings on the furnace is to be construed to be propane HD 5 a commercial grade of liquefied petroleum gases composed of a minimum of 90 percent liquid propane C3Hs Material and Workmanship This furnace was built with the highest quality materials and attention to workmanship However omissions and defects occasionally occur Before installing the furnace inspect the furnace thoroughly If missing parts defective material or poor workmanship are evident report the model and serial numbers imprinted on the furnace rating label to the seller Packaging This is a complete factory assembled furnace contained within one package However certain parts including air filter s air filter rack s the venting system must be assembled to the furnace in the field Shipping Damage If this furnace was damaged during transit please immediately request the transportation company inspect the furnace and issue a concealed damage report The party receiving the furnace should file the claim for shipping damage Rep
56. olution when the gas is turned on following the procedure outlined in this section A final test for gas leakage must be made after purging the gas line Refer to Section Ill E of this manual This test must be conducted with the unit operating and should include the furnace piping and gas valve Never use an open flame to check for a gas leak A CAUTION Care must be taken not to wet electronic components during leak test Wetting the electronic components may damage circuitry and cause a hazardous situation Dry moisture from all leads and terminals if minor wetting occurs Wait at least 24 hours for the circuit to fully dry before energizing the burner circuit The furnace and its individual gas shutoff valve must be disconnected from the gas supply during pressure testing of the gas supply system at pressures in excess of 1 2 PSIG or 14 0 in W C The furnace must be isolated from the gas supply by closing its manual shut off valve at test pressures equal to or less than 1 2 PSIG or 14 0 in W C Do not use a connector which has previously served another gas appliance All gas piping and testing must be performed by a qualified installer or service person The installation must comply with local codes these instructions and the National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or the latest edition thereof 21 All installations and services must be performed by qualified service personnel Piping from the natural gas meter t
57. or 2 Full Basement example of an unconfined space Where a furnace is installed in a full basement infiltration is normally adequate to provide air for combustion and ventilation When an opening in the outside wall must be provided it should be furnished with properly screened metal sleeves If an exhaust fan or additional fuel burning appliances are present in the furnace room there should be increased concern about providing adequate airflow to the furnace Additional efforts may be required to assure an adequate supply of combustion and ventilation air is available to the furnace under all conditions F MDA1 Horizontal Installation WARNING The auxiliary limit switch must be relocated in accordance with the following instructions when installing this furnace horizontally A CAUTION DO NOT hang the horizontal counterflow furnace from a structure or surface by any integral part or fastener of the furnace The furnace was not designed to support itself in this manner The MDA1 50 75 100 and 125 furnaces may be installed in a horizontal position by placing the furnace on the left or right side as viewed from the front in the upright position If the unit is placed on its right side the auxiliary limit switch located on the right side of the house air blower must be moved to the opposite left side of the blower refer to Figure 2 All installations and services must be performed by qualified service personnel
58. or the latest edition thereof 18 All installations and services must be performed by qualified service personnel It is recommended that all single wall vent connectors connected to the MHA1 MDA1 Series furnaces have all seams and joints sealed with high temperature pressure sensitive aluminum tape or high temperature silicone rubber sealant as noted below 1 High temperature aluminum tape having a temperature rating of 480 F or greater 2 Dow Corning 736 General Electric RTV106 sealant or equivalent having a temperature rating of 480 F or greater It is recommended that all vent connectors be insulated with 1 0 thick foil fiberglass or its equivalent to reduce the chance of condensation and prolong the life of the venting system It is mandatory that vent connectors installed in or passing through an unheated space must be insulated in this manner to prevent condensate from forming in the connector or vent K Sidewall Venting AWARNING e The MHA1 MDA1 Series furnaces SHALL NOT BE COMMON VENTED IF SIDEWALL VENTING IS EMPLOYED e Before sidewall venting the MHA1 MDA1 furnace read and understand this section as well as the sidewall vent manufacturers instructions which accompany the venting product Failure to follow these instructions may cause unsafe conditions resulting in property damage personal injury or loss of life e The sidewall venting system must be installed so as to avoid possible contact with concealed pl
59. ort any shipping damage immediately All installations and services must be performed by qualified service personnel It is absolutely essential that a damage report be obtained If a concealed damage report is not obtained we cannot provide assistance in recovering your claim against the transportation company Warranties ZA WARNING The manufacturer of this equipment assumes no liability for any damages resulting from unauthorized modifications made to the furnace or components thereof or improper installation of the furnace in the field Furthermore any such field modifications VOID THE WARRANTY and place the responsibility for safe and reliable operation of the furnace on those who performed the modification s Make certain the warranty cards are returned These must be on file to verify installation dates for replacement of any warranted part s l Safety WARNING The following guidelines and warnings should be read and understood before continuing with the installation of this furnace Failure to follow these guidelines can result in improper and unsafe operation of this appliance which can cause substantial property damage severe personal injury or death These instructions must be read in their entirety before installing the furnace It is the installer s responsibility to do the following 1 Use only with the type of gas approved for this furnace Refer to the furnace marking plate 2 Install this furnace onl
60. outs have been provided on each side casing to act as a template for the cut out Scribe lines connecting the outside corners of each knockout cut side casing along lines Position the open end of the filter rack so that it is accessible for filter replacement Attach the filter rack to the furnace with screws or pop rivets along the securing flange Connect the return plenum to the filter rack and slide the filter into place All installations and services must be performed by qualified service personnel FLANGE FURNACE SIDE SA FLANGE DIMENSIONS p lt DUCT SIDE a SS H W MHA1 50 75 100 15 24 1 2 Pat S MHA1 125 19 24 ES SECURING OPEN END INTO WHICH FILTER SLIDES Figure 3 Optional Thermo Pride Filter Rack I Use of Non Thermo Pride Filter Retention Means ACAUTION Failure to comply with minimum filter installation requirements may affect the performance and or void the warranty on this furnace If a method other than a Thermo Pride filter rack is selected for retention of the filter and or use of a different filter type is desired see Table 2 for minimum size guidelines for selecting a filter system for the MHA1 MDA1 furnaces 10 All installations and services must be performed by qualified service personnel Table 2 Minimum Filter Area Required Sq in Maximum Furnace Model Filter Type pate ot YD Velocity MHA1 50 MHA1 75 MHA1 100 MHA1 125 FPM MDA1 50 MDA1 75
61. owing flash pause sequences to indicate failure status each flash will last approximately 0 25 seconds and each pause will last approximately 2 seconds 1 flash then pause System lockout 2 flashes then pause Pressure switch stuck closed 3 flashes then pause Pressure switch stuck open 4 flashes then pause Open high limit aux limit or roll out switch 6 flashes then pause 115 Volt AC power reversed 7 flashes then pause Low flame sense signal 8 flashes then pause Check ignitor or improper grounding Continuous flashing Flame has been sensed when no flame should no pause be present no call for heat The LED will also flash once at power up 37 All installations and services must be performed by qualified service personnel V Dealer Maintenance SAFETY DURING SERVICING AND INSPECTION WARNING ELECTRICAL SHOCK FIRE OR EXPLOSION HAZARD Failure to follow safety warnings exactly could result in dangerous operation serious injury death or property damage Improper servicing could result in dangerous operation serious injury death or property damage Before servicing disconnect all electrical power to furnace When servicing controls label all wires prior to disconnecting Reconnect wires correctly Verify proper operation after servicing Notice Homeowner user routine maintenance Complete instructions for the homeowner including maintenance procedures which must be performed by the homeowner user can be fo
62. p e aogida 0 21049 Saumo dy Jo Jajeap payl enb Jayjo Aue Jo Jejeep Buljjeysul SUDO y UM aueue Aew saumo ay OJ Sepo oaie sied SIY 9 l JUsUaoR del Olpouied anbe yorym sua BoUeUAaUIEW Jo uoydaox y UIA pa UeeM ale soeWNY y Jo syed e uogeezsu Jeue syjuou 09 45114 EY BULING SLUVd AYIA HLS LSL s 48UMO juanbesans Aue 0 osje pue 977 S NpOId Owy 0 peuuNjes pueg uopensi poy Aueen 2y UO aeoieo sjy uo Jeadde s eweU asoym s aumo JeUIBLIO 94 0 pepuspe S hjueem aul diysueUDJOM pue jenayeu Ul 294 P WO aell aq 0 1 Aq panypeznuew SeoeUINY e wem paly seB ep d oway ey Spueem q s y uogesodioo euelpul ue 977 SJoNpold oway L JaeBueyoxy e H UO owne uonewodsuel pue Syed Jee ed peywiq AjUeUeM SNTd ANIN 40 JOV3d 971 SPNpoId OWWSY
63. ravity of 0 60 or b For commercial propane gas with a higher heating value of 2500 BTU per standard cubic foot and a specific gravity of 1 53 The appliance rating plate inside the burner compartment will specify for which gas the main burner orifices were selected If the appliance is installed at an altitude that is more than 2 000 feet above sea level it is mandatory that the input to the burner be reduced 4 0 for every 1 000 feet that it is above sea level Example A furnace installed at an elevation of 5 000 feet its input must be reduced 20 0 At 5000 ft a total reduction of 5000 ft x 4 per 1000 ft or 20 is required This equates to a reduced firing rate of 80 000 BTUH 100 000 BTUH x 0 80 80 000 BTUH at an elevation of 5 000 feet If the furnace is installed at an elevation of 2 000 feet or less no reduction in input rate is required For high altitude installations your local gas supplier may assist in determining the correct main burner orifice size for the elevation at which the appliance is installed Our Engineering Department will gladly assist in sizing the orifice if the lower heating value in BTU per cubic foot the specific gravity of the fuel gas and the altitude where the appliance will be installed are provided To check the input rate of the furnace allow the unit to operate for 15 minutes and proceed as follows 1 Contact your gas supplier and ask for the BTU content higher heating value of one standar
64. rer ye Ze 1 lae SAFE Y cence ek ea Ae ci dk ch eR tk ct eR ck eR tk ct ek tk tek dete 2 Il INSTALLATION GUIDELINES sese xxx eee 3 Le ee A A EE EA EAEE ETE EE LENE EAA EREE EATE 3 B Installation Location sse eee 4 C Closet and Alcove Installation s Zc R4 T ana aa 4 Dy Standard Clearance S ecne a eiee ee eee ee 5 E Air for Combustion and Ventilation sees eee eee 6 F MDA1 Horizontal Installation sss eee eee 7 G Duct Work and Air Conditioning sss sese eee eee 9 fe Fier Filter te T lt T 9 Use of Non Thermo Pride Filter Retention Means sse eee ee 10 B Venting eet eee eee eet a Perey oe a ede daea PRS Fel SNe May Pen Nee aero 12 T Vertical Venting sassi hedeeeieee ee ROR 12 2 Replacing an Existing Furnace from a Common 13 3 Condensing in GhiImney 2024 Ano Ae eenen 14 4 Vent Flue Vent Connector eee ee eee tt ntreenrnn rnnt rnneeennn nenn 16 K Sidewall VentinG sxstcvouseskcieeweke eee oe eee n 19 1 Horizontal Size and Lengths for Horizontal Vents 20 H AS SAS PIPIN T 21 1 Installation of Natural Gas Piping 23 2 Installation of Propane Gas Piping eee 24 M Tee Le T 26 TAWI Sc coco eer ei i ee In hee oleter tee 26 2 Field Wiring and Replacing Wing 26 3 Electronic Air Cleaner and Humidifier Connections sss eee 27 4 Room Thermostat sese 27 5 Blower Motor Speed Wiring sss eee eee eee 28 Ill INITIAL OPERATION OF THE FURNACE eee 29 Bree WMA SS FALUN coo ig ce bee Eo AEE E EEEE EE E TE T Cahoon oa 29 B Adju
65. rvice personnel J Venting 1 Vertical Venting A WARNING e The vent installation of this Category furnace must be in accordance with National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or latest edition and or local building codes and these instructions e A furnace or any other gas utilization equipment must not be connected to a chimney flue serving a separate appliance designed to burn solid fuel e When venting two or more appliances into a common vent the smallest appliance must be vented into the top opening e The maximum gross stack temperature must not exceed 480 F 249 C under any circumstances NOTICE This section does not apply to units which are sidewall vented For sidewall venting see Section Il K of this manual The following requirements must be followed when connecting this furnace to a vent system The MHA1 MDA1 induced draft gas highboy and counterflow horizontal series furnace must be vented in accordance with these instructions into a factory built chimney or vent complying with a recognized standard Type B1 or double wall vent as well as masonry chimneys lined with a lining material acceptable to the authority having jurisdiction are acceptable as described in the venting tables included in the appendix of the National Fuel Gas Code NFPA 54 ANSI Z223 1 2002 or latest edition A good vent is one that is sealed and has the capability of producing a 0 04 in W G draft with the capacity of handlin
66. services must be performed by qualified service personnel NOTICE restriction leakage corrosion or other deficiencies which could cause an unsafe condition Insofar as is practical close all building doors and windows and all doors between the space in which the appliances remaining connected to the common venting system are located and other spaces of the building Turn on clothes dryers and any appliance not connected to the common venting system Turn on any exhaust fans such as range hoods and bathroom exhausts so they will operate at maximum speed Do not operate a summer exhaust fan Close fireplace dampers Follow the lighting instructions Place the appliance being inspected in operation Adjust thermostat so appliance will operate continuously Test draft hood equipped appliances for spillage of flue gases at the draft hood relief opening after 5 minutes of main burner operation Use the flame of a match or use a draft gauge If the improper venting is observed on any of the appliances during the above testing the common vent system must be corrected Follow the steps outlined in the National Fuel Gas Code NFPA 54 ANSI 2223 1 2002 or the latest edition thereof to resize the vent system to approach the minimum size using the appropriate tables in the appendix of the Code Return doors windows exhaust fans fireplace dampers and the remaining appliances to their previous conditions of use after determin
67. stment of Heat Input Rate 32 BURIED AIC jUS UNIS IN meise mre nreno vk cere ek iene ont fe 8 Ose le ene ee ae a ene aE cel 34 D Setting Supply Air Temperature Rise eee 35 E Checkout Procedure sss sees ee 36 Wr TROUBLESHOOTING TT 37 V DEALER MAINTENANCE 38 PX ICCC Al TT 38 Bi MOORE F al inspection n e e e e e e e a S ate 38 G Housse Air BIOWe ntnuneondndnelrdemed nd ne a E Melee od admin a eE 39 Dy IRetum Air 21 1 e a a a en ten ene cate ates 40 All installations and services must be performed by qualified service personnel VI INSTALLER S INSTRUCTIONS TO USER sss 41 APPENDIX A SOURCES FOR REFERENCED STANDARDS ccc 42 APPENDIX B SEQUENCE OF OPERA ION eee 43 APPENDIX C TROUBLESHOOTING FLOWCHART sse eee eee 45 APPENDIX D PARTS PACKAGE COMPONENTS eect eee 49 APPENDIX E REPLACEMENT PARTS LIST 50 APPENDIX F ELECTRICAL DIAGRAMS eee 54 WARRANTY sess cbc eh ete gs ohre a ceased oe a aaa ia aa i a a 59 All installations and services must be performed by qualified service personnel Notice to the Installer Installation of this gas fired furnace must be performed by a qualified installer in accordance with all local codes and authorities having jurisdiction In the absence of local governing codes installation shall conform to these instructions and to the regulations of the National Fuel Gas Code ANSI Z223 1 NFPA 54 2002 and or National Gas and Propane Installation Codes CSA B149 1 or the latest editions there
68. sure the pressure using a pressure gauge or manometer at the 1 8 in NPT plugged tap on the inlet side of the appliance gas control valve shown in the General Gas Piping Requirements section of this manual An Allen wrench is normally required to remove the plug from the valve Make sure the fuel gas is shut off before removing this plug and installing a pressure test gage Table 8 Allowable Gas Pressures for All MHA1 MDA1 Models Range of Type of Supply satan ressure Fuel Gas Pressure in W G in W G so ee Natural 14 0 4 5 3 5 3 Propane 14 0 11 0 10 0 3 This appliance is equipped with multiple identical fixed main burner orifices sized for the fuel gas and manifold pressure shown on the rating label The input rate can only be increased or decreased by adjusting the manifold pressure To adjust the manifold gas pressure to the main burners a With the gas shutoff remove the 1 8 in NPT threaded pipe plug located on the front side of the main burner gas manifold Use a U tube manometer or pressure gage capable of measuring pressure in inches of water column to measure the gas pressure at this point 33 All installations and services must be performed by qualified service personnel b Turn on the fuel gas and cause the appliance to activate the heating section by answering a call for heat c Allow the heating section to operate for 15 minutes d Note the mani
69. tment procedures if proper flame s are not present C House Air Blower Check and clean the blower wheel housing and compartment with a vacuum Check the motor nameplate and follow motor manufacturer instructions for lubrication if required IMPORTANT Some motors are permanently lubricated and should not be oiled See motor nameplate for specific instructions 39 All installations and services must be performed by qualified service personnel D Return Air Filter The Return Air Filter s Provided with this unit is a permanent type filter This filter s should be inspected and when dirty cleaned or replaced if necessary to assure proper furnace operation Follow the cleaning removal and replacement procedure below Filter Maintenance Procedure The filter rack will be located between the return air plenum and the return air opening of the furnace See Figure 11 for MHA1 MDA 1 series units Slide dirty filter out of the filter rack Clean the filter by vacuuming rinsing with tap water hosing or dipping in an ordinary detergent solution After cleaning replace the completely dry filter in the rack If the filter has a mesh the mesh side of the filter must be towards the furnace y FILTERS RETURN AIR S T RETURN AIR FRONT DOOR __ cy GR BLOWER 4 a ACCESS DOOR COMBUSTIBLE TYPICAL FILTER BE T al FLOOR BASE LA he S LOCATION Si ae MHA1 SERIES oy th
70. to light the burner by hand BEFORE OPERATING smell all around the appliance area for gas Be sure to smell next to the ground because some gas is heavier than air and will settle on the ground WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance Do not touch any electric switch do not use any phone in your building Immediately call your gas supplier from a neighbor s phone Follow the gas supplier s instructions e f you cannot reach your gas supplier call the fire department Use only your hand to operate the gas control valve knob or if equipped the gas control valve switch Never use tools If the knob or lever will not move don t try to repair it call a qualified service technician Forced or attempted repair may result in a fire or explosion Do not use this appliance if any part has been under water Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control that has been under water 30 All installations and services must be performed by qualified service personnel Operating Instructions STOP Read the safety information above Set the thermostat to the lowest setting Turn off all electric power to the appliance This appliance is equipped with a hot surface igniter that automatically lights the burner Do not try to light the burner by hand The burner compartment cover must first be removed before the gas contro
71. try 43 All installations and services must be performed by qualified service personnel Mode of Operation Main Burner Operation Repeated Trials for Ignition Y Call for Heat Satisfied System Lockout Y End of Cycle Control System Action After delay to fan on period ends circulating air fan is energized at heating speed The optional electronic air cleaner and humidifier are energized U When thermostat is satisfied contacts open and the gas valve is de energized After proof of flame loss inducer and optional humidifier are de energized The delay to fan off period begins 180 seconds y After the delay to fan off period ends the circulating air fan and optional electronic air cleaner are de energized 44 y If ignition attempt is unsuccessful one more retry will be made before the ignition control module goes into system lockout If flame is detected then lost the ignition control module will repeat the initial ignition sequence for a total of four recycles After four unsuccessful recycle attempts the control will go into system lockout The ignition control module will reset automatically in 60 minutes If system is in lockout try to reset by interrupting the power to the furnace at the disconnecting switch or interrupting the call for heat at the thermostat If this does not restart the system refer t
72. umbing or electrical wiring e Alljoints between sections or fittings of the vent system must be sealed as recommended by the vent manufacturer e The proper operation of the vent system and appliance requires part specified by the vent or appliance manufacturer with no deletions or substitutions The MHA1 MDA 1 series furnaces are approved for sidewall venting using only Field Controls SWGII Power Venter Kit specified below Model SWGII 4HD Power Venter and CK 43F Control Kit FIELD CONTROLS 2630 AIRPORT ROAD KINSTON NC 28504 252 522 3031 AUTOMATED LITERATURE FAX 1 800 385 9460 All installations and services must be performed by qualified service personnel Installation setup and operation must be in accordance with the instruction provided by the manufacture of the power venter Thermo Products has provided in the following section maximum and minimum vent lengths guidelines that must also be followed Contact Field Controls for instructions for installing the SWGII vent system IMPORTANT No warranty will be made on behalf of the appliance manufacturer with respect to the sidewall venting system installation or replacement The appliance manufacturer shall not be liable for any special incidental indirect or consequential damages Some jurisdictions do not allow exclusion or limitation of incidental or consequential damages The above limitations or exclusions may not apply to you IMPORTANT It is the installers r
73. und in the Users Information Manual The following maintenance procedures should be performed at the beginning of each heating season by a qualified heating contractor Correct any deficiencies at once A Electrical 1 Check all wiring for loose connections and any signs of damage or unusual wear 2 Check for correct voltage at the furnace when operating 3 Check amp draw on blower motor and inducer motor to assure they are not exceeding nameplate amp rating 4 Check for correct operation and proper settings if manually adjustable of all controls Shut off gas and disconnect power before continuing B General Inspection 1 lInspect the heat exchanger for evidence of corrosion pitting warpage deterioration and carbon build up Also look for loose gaskets in the flue pipe burner box and accessible areas of the heat exchanger 38 All installations and services must be performed by qualified service personnel 2 Chimney vent pipe Vertically vented units Remove flue pipe from inducer and inspect for restriction loose joints carbon build up and condensation Clean vent and chimney if necessary and replace or repair any degraded vent vent connector or chimney damage found For sidewall vented units refer to the manufacturer s maintenance instructions for the sidewall venter 3 Burners If it appears that material is accumulating in the burner box the box and burners can be vacuumed If necessary the burners
74. urnace depends on correct polarity The hot leg of the supply circuit must be connected to the black line lead and the common leg to the white line lead in the field mounted junction box The hot leg must be connected through the disconnect switch in all cases to prevent the hazard of electrical shock when servicing 2 Field Wiring and Replacing Wiring Field wiring between the furnace and devices not attached to the furnace shall conform to the temperature limitation for Type T wire 63 F 35 C rise when installed with the manufacturers instructions If any of the original factory supplied furnace wiring is replaced or a separate device other than the thermostat is wired internal to the unit 105 C temperature rated thermoplastic insulated wire or equivalent wire must be used 26 All installations and services must be performed by qualified service personnel 3 Electronic Air Cleaner and Humidifier Connections The ignition module on this furnace has designated terminals to control the operation of an electronic air cleaner and or humidifier These terminals provide line voltage for the control of these accessories See Figure 8 NOTICE It is important to confirm that the operating voltage of the humidifier or EAC being installed matches the output of this control If not a field supplied relay or transformer may be necessary to provide the proper control and supply voltage for the accessory being installed See the manufacturers i
75. use these chemicals in the same space as the furnace all containers should be sealed when not in use If possible keep these chemicals in a separate well ventilated room that is closed off from the furnace with a door The furnace shall be installed in a location within the building that permits a satisfactory supply of air for combustion ventilation and proper operation of the venting system While all forms of building construction cannot be covered in detail in this manual this requirement may usually be met by application of one of the following methods in ordinary building construction Consult the National Fuel Gas Code NFPA 54 ANSI 2223 1 2002 or the latest edition for special cases and further details However local installation codes always take precedence and must be followed if applicable All installations and services must be performed by qualified service personnel 1 Utility Room example of a confined space In buildings of unusually tight construction such as those wherein weather stripping and storm sash windows are used two 2 permanent openings connecting to a well ventilated crawl space attic or with the outdoors shall be provided Each opening shall have a minimum free area of one 1 square inch per 1000 BTUH of total input rating of all appliances to be installed in the utility room One opening should be located near or in the ceiling of the room and the other should be located near or in the flo
76. y in a location and position as specified in Section Il B of this manual 3 Provide adequate combustion and ventilation air to the furnace space Refer to Sections II E of this manual 4 Connect this furnace to an approved vent system only Combustion products must be vented outdoors Refer to Section Il J of this manual for vertical vented units All installations and services must be performed by qualified service personnel 5 10 11 12 Never test for gas leaks with an open flame Use a commercially available soap solution made specifically for the detection of leaks to check all connections Refer to Section Il L of this manual Always adjust the furnace to operate within the furnace s temperature rise range with a duct system which has an external static pressure within the allowable range Refer to Section IIl D of this manual Make sure supply and return air ducts are completely sealed to the furnace casing Ductwork must run to an area outside the air space where the furnace is located and be sealed where it runs through walls ceilings and floors Refer to Section Il G of this manual This furnace is not to be used for temporary heating of buildings or structures under construction Refer to MDA1 horizontal application Section II F of this manual for safety switch relocation associated with horizontal installation of the MDA1 Inform and demonstrate to the user the correct operation and maintenance o

Thermo Products MHA1-125N Furnace User Manual

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