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Service Manual 11/2011

1. LENNOX UNIT INFORMATION SL280DFV aa A Corp 1117 L4 Service Literature Revised 11 2011 icomfort ENABLED SL280DFV SERIES UNITS SL280DFV series units are 80 efficiency gas furnaces used for downflow applications only manufactured with Lennox Duralok heat exchangers formed of aluminized steel Units are available in heating capacities of 66 000 to 110 000 Btuh and cooling applications up to 5 tons Refer to Engineering Handbook for proper sizing Units are factory equipped for use with natural gas Kits are available for conversion to LPG operation SL280DFV mod el units are equipped with the icomfort enabled Sur eLight two stage variable speed integrated control Alll units use a redundant gas valve to assure safety shut off as required by CSA All specifications in this manual are subject to change Pro cedures outlined in this manual are presented as a recom mendation only and do not supersede or replace local or state codes In the absence of local or state codes the guidelines and procedures outlined in this manual except where noted are recommendations only and do not consti AWARN G tute code Improper installation adjustment alteration service TABLE OF CONTENTS or maintenance can cause property damage person al injury or loss of life Installation and service must Specifications Page 2 be performed by a licensed professional installer or equivalent s
2. 1 r Demand Pa High pcr setpoint by allowing the room space to maintain a cooler room thermo stat setpoint ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING BASIC MODE only active on a Y1 thermostat demand 24 ComfortSense 7000 UENIRE 7 ATS Y2 and de energizes D i call for de humidi PRECISION MODE operates independent of a Y1 thermostat demand i 24 60 65 7 5 begins when humidity ca 0 Dehumidification D d High 60 65 ComfortSense 7000 call ONLY eman ae ig 70 thermostat will try to maintain room humidity Jumpers at indoor unit with a two stage outdoor unit setpoint by allowing the Cut factory jumper from Y1 to Y2 or cut W915 Y1 to Y2 room space to maintain With Condensing unit Cut W914 R to DS on SureLight board a cooler room thermo With Heat Pump Cut W914 R to DS amp W951 R to O on SureLight control stat setpoint Comments ComfortSense 7000 thermostat to use for this application Y2081 4 heat 2 cool Normal operation first stage cooling blower speed is 7096 COOL speed Dehumidification blower speed is reduced to 7096 of COOL In Precision mode ComfortSense 7000 thermostat will maintain room temperature up to 2 F 1 2 C cooler than room setting Page 19 B Indoor Blower Motor S ly Air BI up fa del secondary blower wheel 2 m oto r an a 222 5 E To Remove Blow
3. A Cubic feet per minute cfm setting for indoor blower 1 second ON 0 5 second OFF cfm setting for current mode displayed C Cooling stage 1 second ON 0 5 second OFF 1 or 2 displayed Pause cfm setting displayed Pause Repeat codes Dehumidification mode 1 second ON 1 second OFF cfm setting dis played Pause Repeat Codes h Heat pump stage 1 second ON 0 5 second OFF of input rate dis played Pause cfm setting Pause Repeat codes Gas Heat Stage 1 second ON 0 5 second OFF 1 or 2 displayed Pause cfm setting displayed Pause Repeat codes Blinking during ignition Defrost mode Discharge Air Temperature E 105 Device communication problem No other devices on RS BUS Commu Equipment is unable to communicate Indicates nication numerous message errors In most cases errors are power is separated from RSBus Check for mis System related to electrical noise Make sure high voltage wired and or loose connections between the stat indoor unit and outdoor unit Check for a high volt age source of noise close to the system Fault clears after communication is restored E 110 Low line voltage Line Voltage Low Voltage lower than nameplate rating Check power line voltage and correct Alarm clears 5 seconds after fault recovered E111 Line voltage polarity reversed Reverse line power voltage wiring System resumes normal operation 5 seconds after fault recovered Groun
4. WHITE RODGERS GAS VALVE HIGH FIRE ADJUSTMENT MANIFOLD SCREW under cap INLET PRESSURE POST PRESSURE TAP 3r GAS VALVE SHOWN IN ON POSITION FIGURE 13 HONEYWELL GAS VALVE INLET PRESSURE TAP HIGH FIRE ADJUSTING SCREW ON SIDE under cap US O bos MANIFOLD GAS VALVE SHOWN IN ON POSITION FIGURE 14 8 Turn switch on gas valve to ON Do not force See fig ure 13 or 14 9 Replace the upper access panel 10 Turn on all electrical power to to the unit 11 Set the thermostat to desired setting NOTE When unit is initially started steps 1 through 11 may need to be repeated to purge air from gas line Turning Off Gas To Unit 1 Setthermostat to lowest setting 2 Turn off all electrical power to unit if service is to be per formed 3 Remove access panel 4 Turn switch on gas valve to OFF Do not force See fig ure 13 or 14 5 Replace access panel Failure To Operate If the unit fails to operate check the following 1 Is the thermostat calling for heat 2 Are access panels securely in place 3 Is the main disconnect switch closed 4 s there a blown fuse or tripped circuit breaker 5 Is the filter dirty or plugged Dirty or plugged filters will cause the limit control to shut the unit off 6 Is gas turned on at the meter 7 Is the manual main shut off valve open 8 Is the internal manual shut off valve
5. Increase 1896 Increase 1296 Increase 6 Factory Default Decrease 696 Decrease 1296 Decrease18 Switches 14 and 15 Continuous Blower Speed Table 11 provides continuous blower speed adjustments that will result from different switch settings TABLE 11 Continuous Blower Speed Continuous Blower Speed 38 of High Cool Speed Factory 100 of High Cool Speed BLOWER DATA SL280DF070V36A BLOWER PERFORMANCE less filter 0 through 0 8 in w g Heating and 0 through 1 0 in w g Cooling External Static Pressure Range HEATING Heating Speed DIP Switch First Stage Heating Speed cfm Second Stage Heating Speed cfm Settings 24 1065 1170 18 1010 1115 12 960 1055 6 910 1000 Factory Default 860 945 6 805 885 12 755 830 18 705 775 1 Cooling Speed First Stage Cooling Speed cfm Second Stage Cooling Speed cfm eae Low Medium Low Medium High High Low Medium Low Medium High 2 High 745 870 1025 1075 1100 1240 1425 1515 Factory Default 665 780 925 985 1015 1115 1305 1380 590 690 815 865 900 1025 1170 1250 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control Refer to Installation Instructions for specific DIP Switch Settings Factory default setting NOTES The effect of static pressure is included in air volumes shown First stage HEAT is approximately 91 of the same second
6. The blower on delay of 30 seconds is not adjustable The blower off delay time that the blower operates after the heating demand has been satisfied can be adjusted by moving switches 3 and 4 on the integrated control The unit is shipped from the factory with a blower off delay of 90 seconds The blower Secondary voltage is below 18VAC After 10 min utes operation is discontinued Clears the code after voltage is higher than 20 VAC for 2 seconds or after power reset off delay affects comfort and is adjustable to satisfy individ ual applications Adjust the blower off delay to achieve a supply air temperature between 90 and 110 F at the exact moment that the blower is de energized Longer off delay settings provide lower supply air temperatures shorter set tings provide higher supply air temperatures Table 6 pro vides the blower off timings that will result from different switch settings TABLE 6 Blower Off Delay Switch Settings Blower Off Delay Switch 3 ee 120 90 Factory Lee or 120 0 Indoor Blower Operation DIP Switch Settings Switches 5 and 6 Cooling Mode Blower Speed The unit is shipped from the factory with the dip switches posi tioned for high speed 4 indoor blower motor operation during the cooling mode Table 7 provides the cooling mode blower speeds that will result from different switch settings Switches 5 and 6 set the blower cfm for second stage cool The
7. Gas LPG Propane Low Input Btuh 43 000 57 000 57 000 72 000 Pire Output Btuh 35 000 46 000 46 000 59 000 Temperature rise range F 25 55 25 55 25 55 25 55 Gas Manifold Pressure in w g 1 7 4 9 1 7 4 9 1 7 4 9 1 7 4 9 Nat Gas LPG Propane High static in w g Heating 0 8 0 8 0 8 0 8 Cooling 1 0 1 0 1 0 1 0 Connections Flue connection in round 4 4 4 4 Gas pipe size IPS 1 2 1 2 1 2 1 2 Indoor Wheel nominal diameter x width in 10x8 11x9 11x 10 11 x 10 Blower Motor output hp 1 2 1 1 1 Tons of add on cooling 2 3 3 4 3 5 5 3 5 5 Air Volume Range cfm 589 1514 830 1996 899 2273 882 2120 Electrical Voltage 120 volts 60 hertz 1 phase Data Blower motor full load amps 7 7 12 8 12 8 12 8 Maximum overcurrent protection 15 20 20 20 Shipping Data Ibs 1 package 130 153 164 173 NOTE Filters and provisions for mounting are not furnished and must be field provided 1 Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations Isolated combustion system rating for non weatherized furnaces OPTIONAL ACCESSORIES MUST BE ORDERED EXTRA A Width B Width C Width Models Models Models CABINET ACCESSORIES Downflow Combustible Flooring Base 11M59 11M60 11M61 CONTROLS ComfortSense 7000 Thermostat Y0349 Y0349 Y0349 Remote Outdoor Sensor for dual fuel Humiidtrol X2658 X2658 X2658 DOWNFLOW FILTER KITS Downflow Filter Kit 51W06 51W
8. The control and ignitor work in combination to ensure furnace ignition and ignitor durability The control provides gas ignition safety checks and indoor blower control with two stage gas heating The furnace combustion air inducer gas valve and indoor blower are controlled in response to various system inputs such as thermostat signal pressure and limit switch signal and flame signal The control features a seven seg ment LED display indicating furnace status including in door blower and error codes The LED flashes in single digits For example using table 5 under LIMIT CODE an E followed by 2 followed by 5 followed by 0 the limit Switch circuit is open The control also has two unpowered dry 1 4 contacts for a humidifier and a 120 volt accessory terminal Both rated at 1 one amp each Electronic Ignition At the beginning of the heat cycle the integrated control monitors the first stage and second stage combustion air inducer prove switch The control will not begin the heating cycle if the first stage prove switch is closed by passed Likewise the integrated control will not begin the second stage heating cycle if the second stage prove switch is closed and will remain in first stage heat However if the second stage prove switch closes during the first stage heat pre purge the control will allow second stage heat Once the first stage prove switch is determined to be open the combustion air inducer is ene
9. a 15 second pre purge the high fire pressure switch will close and the unit will begin operation on high fire After 20 seconds of high fire operation the unit will switch to low fire SureLight control begins 20 second ignitor warm up period Gas valve opens on first stage for a 4 second trial for ignition Ignitor stays energized during the trial or until flame sensed Flame is sensed gas valve remains on first stage heat ignitor de energizes After 45 second delay indoor blower B3 is energized on low heat speed The furnace will stay in this mode until first stage de mand is satisfied OR a second stage heat demand is initiated Second stage heat demand initiated A 30 second sec ond stage recognition period begins The combustion air inducer ramps up to high heat speed 102 high heat prove switch closes and the gas valve energizes second stage heat B3 indoor blower ramps up to high heat speed Page 35 Single Stage Thermostat Two Stage Heat DIP 1 Switch set at SINGLE SureLight control energizes combustion air inducer BG on low heat speed Combustion air inducer runs until 128 low heat prove switch contacts close switch must close within 2 1 2 minutes or control goes into Watchguard Pressure Switch mode High heat prove switch 5102 may also close 15 second pre purge follows once 128 closes NOTE If the low fire pressure switch does not close the combustion air inducer will switch to high fire After a 15 sec
10. cating outdoor unit Dual fuel module required for heat pump applica Replace link or hard wire Applicable in non com tion municating mode Critical Alert 370 Interlock switch sensed open for 2 minutes Control sees the loss of 24VAC for 2 minutes Ter minate all services and wait for interlock switch to E 349 No 24 Volts between R amp O on integrated control with non communi Configuration link R to O needs to be restored close The alarm will clear when 24VAC is continu ously sensed on DS terminal for a minimum of 10 seconds or on a power reset Clears the error after current is sensed in both RUN and START sensors for at least 2 seconds E400 LSOM Compressor internal overload tripped Thermostat demand Y1 is present but compres Sor is not running Check power to outdoor unit or after service is removed or after power reset the error after 30 consecutive normal run cycles or power reset Also monitors low pressure switch E401 LSOM Compressor long run cycle or low system pressure Compressor ran more than 18 hours to satisfy a single thermostat demand Critical Alert Clears trips compressor overloaded Clears the error after 4 E402 LSOM Outdoor unit system pressure trip Discharge or suction pressure out of limits or consecutive normal compressor run cycles Outdoor unit pressure trip thermostat demand Clears the error after 4 con E403 LSOM Compressor short cycling Running less than 4 m
11. AIR HTG CFM FACTORY DEFAULT DECREASE AIR HTG CFM INTEGRATED CONTROL CONFIGURATION GUIDE CLG BLOWER SPEED ADJUSTMENT 2ND STAGE HEAT ON DELAY DIAGNOSTIC PUSH BUTTON OUTDOOR EOUIPMENDOOR EQUIPMENM ON BOARD LINK OPTION SELECTIQ 1 STG COMPRESSOR UNIT W915 2 STAGE COMPR W951 DO NOT CUT EAT UMP DO NOT CUT 2 STAGE HEAT PUMP LINK COMPRESSOR LINK JUMPERS R to O JUMPERS Y1 to Y2 w951 w915 C C C C NEUTRAL DIAGNOSTIC LED NO HARMONY ZONIN OR NO SIGNATURESTA W DS CONNECTION DO NOT CUT W914 OR SIGNATURESTAT DS CONNECTION CUT LINK DEHUMIDIFICATION HARMONY LINK JUMPERS R to DS W914 FIGURE 5 Page 7 CONTINUOUS FAN MODE BLOWER SPEED MEDIUM LOW SPEED 38 MEDIUM HIGH SPEED 70 LOW SPEED 2894 HIGH SPEED 100 COOLING MODE BLOWER SPEED MEDIUM HIGH SPEED MEDIUM LOW SPEED OPTIONA OFF 50 82 100 50 OFF 8296 10096 OFF OPTION C OFF 100 100 OF I OPTION D OFF 100 OFF A CUT ON BOARD LINK SOLDER TRACE COMPLETELY THROUGH BOTH LAYERS ON THE CONTROL BOARD LINKS CUT IN ERROR INSTALL A JUMPER ON THE APPROPRIATE TERMINALS ON THE TERMINAL STRIP PROTECTIVE PLASTIC FILM ON DIP SWITCHES MAY BE REMOVED FOR EASE IN SETTING OF DIP SW FACTORY DEFAULT TABLE 4 Integrated Control Diagnostic Modes Display Action
12. RELAY TAILS SWITCH ENABLED SL280DFV FURNACE icomfort OTHER OUTDOOR CONNECTIONS REMAIN THE SAME REFER TO LVCS VENTILATION CONTROL SYSTEM SPECIFIC DIAGRAM SEE LVCS VENTILATION INSTRUCTIONS FOR DAMPER amp SENSOR WIRING 26156 CURRENT 2 STAGE FURNACE SENSING RELAY KIT ENABLED Ips now COMMUNICATING FREE SYSTEM WIRING PASS INDOOR BLOWER MOTOR COMMON WIRE THROUGH CURRENT LOOP SL280DFV FURNACE icomfort FIGURE 1 Page 37 VIII Program Unit Capacity Size Mode Power Up Number displayed represents by integrated control unit size code furnace model and capacity If three horizontal bars are displayed followed by continuous E203 furnace 3 control does not recognize unit size code Configure per the following To enter Program Unit Capacity Size push and hold button next to 7 segment LED display Fe until solid P symbol appears Release button IMPORTANT Field replacement controls may need to be manually configured to validate Furnace control in IDLE mode No heating cooling or indoor fan 2 X operation Turn room thermostat to OFF furnace unit size code is d stats EN _ Segment LED 7 M Push
13. UV light applications An additional transformer for UV light icomfort Touch applications is required THERMOSTAT C5 NC T10 N C 10 R T11 XS HUM COM T12 i i COM 6 152 12 us 24V IN jumper not used in non HRV3 OR ERV3 communicating configuration OUTDOOR EQUIPMENT INDOOR EQUIPMENT BLACK 9 MONIA icomfort ENABLED OUTDOOR AIR CONDITIONING OR HEAT PUMP UNIT DEHUMIDIFIER CONTROL ENABLED 20 QC I Lj EN CONDENSATE overrLow POWER COMPANY INTERRUPTION SYSTEMS switch ARE WIRED SAME AS OVERFLOW SWITCH SL280DFV FURNACE OUTDOOR UNIT icomfort HCWH 2 429yAC AUXILIARY DEHUMIDIFIER HVAC EQUIPMENT diINOA OVAH u55s5 30 JH HEPA BYPASS FILTER X2680 HEPA INTERLOCK KIT STANDARD 1 OR 2 PASS INDOOR BLOWER STAGE OR HP UNIT e MOTOR COMMON WIRE CURRENT THROUGH CURRENT LOOP 7 lt SENSOR SEE HEPNINTERLOGIEKIT gt x NON COMMUNICATING CO HEPA oL FOR INSTALLATION DE J CONDENSATE f SYSTEM WIRING OVERFLOW
14. air pressure switch first and sec ond stage located on the combustion air inducer orifice bracket The switch is connected to the combustion air in ducer housing by means of a flexible silicone hose It moni tors negative air pressure in the combustion air inducer housing The switches are a single pole single throw proving switch electrically connected to the furnace control The purpose of the switch is to prevent burner operation if the combustion air inducer is not operating or if the flue becomes obstructed On heat demand first or second stage the switch senses that the combustion air inducer is operating It closes a cir cuit to the furnace control when pressure inside the com bustion air inducer decreases to a certain set point Set points vary depending on unit size See table 16 The pressure sensed by the switch is negative relative to atmo spheric pressure If the flue becomes obstructed during op eration the switch senses a loss of negative pressure pressure becomes more equal with atmospheric pres sure and opens the circuit to the furnace control and gas valve A bleed port on the switch allows relatively dry air in the vestibule to purge switch tubing to prevent condensate build up NOTE The switch is factory set and is not field adjust able It is a safety shut down control in the furnace and must not be by passed for any reason If switch is closed or by passed the control will not initiate ignition
15. designated by the positions of DIP switches 11 and 12 When the SL280DFV is running on second stage cool or first stage cool second stage cool is 70 of first stage cool the indoor blower will run on the cooling speed designated by the positions of DIP switches 5 and 6 B Temperature Rise Temperature rise for SL280DFV units depend on unit input blower speed blower horsepower and static pressure as marked on the unit rating plate The blower speed must be set for unit operation within the range of TEMP RISE F listed on the unit rating plate for high fire and low fire To Measure Temperature Rise 1 Place plenum thermometers in the supply and return air plenums Locate supply air thermometer in the first hori zontal run of the plenum where it will not pick up radiant heat from the heat exchanger 2 Set thermostat to highest setting Confirm unit is on high fire by checking rate 3 After plenum thermometers have reached their high est and steadiest readings subtract the two readings The difference should be in the range listed on the unit rating plate If the temperature is too low decrease blower speed 4 Repeat on low fire Do not adjust low fire manifold pres sure C External Static Pressure 1 Taplocations shown in figure 16 STATIC PRESSURE TEST 2 Punch a 1 4 diameter hole in supply and return air ple nums Insert manometer hose flush with inside edge of hole or insulation Seal around the hose
16. open 9 Is the unit ignition system in lock out If the unit locks out again call the service technician to inspect the unit for blockages 10 Is pressure switch closed Obstructed flue will cause unit to shut off at pressure switch Check flue and outlet for blockages 11 Are flame rollout switches tripped If flame rollout switches are tripped call the service technician for in spection C Safety or Emergency Shutdown off unit power Close manual and main gas valves D Extended Period Shutdown Turn off thermostat or set to UNOCCUPIED mode Close all gas valves both internal and external to unit to guaran tee no gas leak into combustion chamber Turn off power to unit All access panels and covers must be in place and se cured Page 27 IV HEATING SYSTEM SERVICE CHECKS A CSA Certification All units are CSA design certified without modifications Refer to the SL280DFV Installation Instruction B Gas Piping ACAUTION If a flexible gas connector is required or allowed by the authority that has jurisdiction black iron pipe shall be installed at the gas valve and extend outside the furnace cabinet The flexible connector can then be added between the black iron pipe and the gas supply line A WARNING Do not exceed 600 in Ibs 50 ft lbs torque when at taching the gas piping to the gas valve Gas supply piping should not allow more than 0 5 W C drop in pressure between gas meter and unit Su
17. should read 120 volts 10 If voltage is above these values check for correct supply voltage to furnace FIGURE 11 Page 25 8 Combustion Air Inducer B6 All units use a two stage combustion air inducer to move air through the burners and heat exchanger during heating op eration The blower uses a 120VAC motor The motor oper ates during all heating operation and is controlled by fur nace blower control A92 The inducer also operates for 15 seconds before burner ignition pre purge and for 5 sec onds after the gas valve closes post purge The inducer operates on low speed during first stage heat then switches to high speed for second stage heat NOTE Each furnace model uses a unique CAI Refer to Lennox Repair Parts listing for correct inducer for re placement A pressure switch connected to the combustion air inducer orifice plate is used to prove inducer operation The combus tion air inducer orifice will be different for each model See table 15 for orifice sizes The switch monitors air pressure in the inducer housing During normal operation the pressure in the housing is negative If pressure becomes less negative signifying an obstruction the proving switch opens When the proving switch opens the furnace control A92 immedi ately closes the gas valve to prevent burner operation TABLE 15 SL280DFV Unit Orifice Size 9 Combustion Air Inducer Pressure Switch S18 18 is a dual combustion
18. stage HEAT First stage COOL two stage air conditioning units only is approximately 7096 of the same second stage COOL speed position Continuous Fan Only speed is selectable at 28 38 70 and 100 of the selected second stage cooling speed minimum 500 cfm Lennox Harmony III Zone Control Applications Minimum blower speed is 425 cfm SL280DF090V48B BLOWER PERFORMANCE less filter 0 through 0 8 in w g Heating and 0 through 1 0 in w g Cooling External Static Pressure Range HEATING Heating Speed DIP Switch First Stage Heating Speed cfm Second Stage Heating Speed cfm Settings 24 1360 1500 18 1285 1415 12 1220 1350 6 1135 1285 Factory Default 1075 1200 6 1030 1110 12 960 1050 18 890 975 1 Cooling Speed First Stage Cooling Speed cfm Second Stage Cooling Speed cfm pa Low Medium Low Medium High High Low Medium Low Medium High High 740 905 1040 1220 1085 1330 1545 1730 Factory Default 690 820 950 1110 990 1200 1400 1 595 610 745 855 1005 895 1075 1270 1460 1 Cooling and heating speeds based a combination of DIP switch settings on the furnace control Refer to Installation Instructions for specific DIP Switch Settings Factory default setting NOTES The effect of static pressure is included in air volumes shown First stage HEAT is approximately 91 of the same second stage HEAT First stage COOL two stage air condition
19. 07 51W08 No and Size of filter in 1 20 x 16 x 1 2 20 x 20 x 1 2 20 x 20 x 1 NIGHT SERVICE KITS Night Service Kit 84W46 84W46 84W46 Safety Service Kit 89W19 89W19 89W19 GAS HEAT ACCESSORIES Models Natural Gas to LPG Propane Kit LPG Propane to Natural Gas Kit all 51W02 69W79 Page 2 z lt Q z o 4 BLOWER ASSEMBLY SECONDARY LIMIT GASKET FLUE CHASE CONTROL BOX Includes two stage integrated control transformer and circuit breaker INTERNAL FLUE PIPE ASSEMBLY DOOR INTERLOCK SWITCH PRIMARY LIMIT LOCATION HEAT EXCHANGER ROLLOUT SWITCH COMBUSTION AIR INDUCER PRESSURE SWITCHES COMBUSTION AIR INDUCER GAS VALVE INNER BLOWER ACCESS PANEL BURNER BOX ASSEMBLY ACCESS PANEL FIGURE 1 Page 3 I UNIT COMPONENTS Unit components are shown in figure 1 The gas valve combustion air inducer and burners can be accessed by re moving the access panel Electrical components are in the control box figure 2 found in the blower section CAUTION Electrostatic discharge can affect elec tronic components Take precautions to neutralize electrostatic charge by touching your hand and tools to metal prior to handling the control A Control Box 1 Control Transformer T1 A transformer located in the control box provides power to the low voltage section of the unit Transformers on all models are rat
20. 1 must be cut when the furnace is installed in applications which include a heat pump unit and a thermostat which features dual fuel use If the link is left intact terminal O will remain ener gized eliminating the HEAT MODE in the heat pump On Board Link W915 2 Stage Compr Y1 to Y2 On board link W915 is a clippable connection between ter minals Y1 and Y2 on the integrated control W915 must be cut if two stage cooling will be used If the Y1 to Y2 link is not cut the outdoor unit will operate in second stage cooling only TABLE 12 SL280DFV Non Communicating Thermostat with Humidity Control Feature and Single Stage Outdoor Unit OPERATING SEQUENCE SYSTEM DEMAND SYSTEM RESPONSE System Condition NO CALL FOR DEHUMIDIFICATION Normal Operation BASIC MODE only active on a Y1 thermostat demand Thermostat Demand Relative Humidity Step Compres Blower CFM Comments COOL 24 Compressor and indoor 1 On On Acceptable High 10096 blower follow thermostat VAC demand Normal Operation 1 On On Acceptable Ad High 100 ComfortSense 7000 ther mostat energizes Y1 and Dehumidification 0 60 65 de energizes D on a call PRECISION MODE operates independent of a Y1 thermostat demand i 24 7 50 659 gins when humidity is Dehumidification call 1 lonlonlo D d 0 High 60 65 ComfortSense 7000 ther ONLY n pm eman VAC 19 70 mostat will try to maintain room humidity setpoint by allowing the room spa
21. Fuel Single Stage Heat Pump ComfortSense 7000 L7742U thermostat w dual fuel capa bilities Capable of 2 stage gas heat control w dehu midification control Dual Fuel Two Stage Heat Pump ComfortSense 7000 L7742U thermostat w dual fuel capa bilities Capable of 2 stage gas heat control w dehu midification Connect W1 to W1 ONLY if using defrost tempering kit 67M41 DIP Switch 1 Thermostat Heating Stages On Board Links Must Be Cut To Select System Options CUT ON BOARD LINK HARMONY CUT ON BOARD LINK 915 2 STAGE COMPR CUT ON BOARD LIN W951 HEAT PUMP CUT ON BOARD LINK Wiring Connections FURNACE TERM STRIP FURNACE TERM STRIP HEAT PUMP outdoor sensor HEAT PUMP NOTE Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the SL280 integrated control Page 42 X Troubleshooting Troubleshooting Heating Sequence of Operation CALL FOR FIRST STAGE HEAT CALL FOR 1ST STAGE HEAT LOW FIRE INDOOR BLOWER OFF AFTER HEAT FAN OFF DELAY LOW HEAT SPEED INDOOR BLOWER OFF ERROR INDOOR AFTER HEAT FAN CODE BLOWER OFF DELAY LOW FLASHES oN OW HEAT HEAT SPEED P D WATCHGUARD ERROR CODE FLASHES INDUCER ON ROLLOUT HIGH SPEED DE ENERGIZE CODE CIRCUITS GAS VALVE INDOOR BLOWER FLASHES ON LOW HEAT P D INDUCER OFF AFTER POST ERROR CODE PURGE FLASHES AFTER 5 SECONDS INDOOR BLOWER OFF AFTER HEA
22. ING INSULATION THICKNESS AND TERMINATION A EQUIPMENT ND GROU LINE VOLTAGE FIELD INSTALLED CLASS ll VOLTAGE FIELD WIRING DENOTES OPTIONAL COMPONENTS 537420 01 Litho U S A Page 34 A Sequence of Operation Sequence depends on type thermostat used SL280DFV units are applicable for single stage or two stage thermostats Both type thermostats are de scribed below Thermostat DIP switch selection dic tates which mode unit will operate in See flow chart for more sequence detail SureLight Control Self Check When there is a call for heat the SureLight integrated con trol runs a self check The control checks for S10 primary limit S21 secondary limit s and S47 rollout switch nor mally closed contacts The control also checks for S102 high heat and 5128 low heat prove switch normally open contacts Once self check is complete and all safety Switches are operational heat call can continue Two Stage Thermostat Two Stage Heat DIP Switch 1 set at TWO SureLight control energizes combustion air inducer BG on low heat speed Combustion air inducer runs until 128 low heat prove switch contacts close switch must close within 2 1 2 minutes or control goes into Watchguard Pressure Switch mode High heat prove switch 5102 may also close 15 second pre purge follows once 128 closes NOTE If the low fire pressure switch does not close the combustion air inducer will switch to high fire After
23. IRED amen OPTIONAL OUTDOOR AIR SENSOR FOR USE WITH HU MIDIFIER IF NOT ALREADY IN THE SYSTEM FOR OTHER FUNCTIONS BUILT INTO ALL icomfort by Lennox OUT DOOR UNITS A HUM CONTACT IS 120VAC CLOSED ANYTIME N HUMIDIFIER HUMIDITY DEMAND IS PRESENT FURNACE ONLY L1 OTHER 120VAC ACC OUTPUT ISI 120VAC AIR ENERGIZED ANYTIME NEUTRAL CLEANER BLOWER IS RUNNING icomfort ENABLED SL280DFV FURNACE 24V HUMIDIFIER CONNECTIONS HCWB2 HCWB3 HCWP3 24VAC 4 HUMIDIFIER Discharge Air Sensor Required for even heat d DISCHARGE AIR SENSOR CS 7000 48G95 RELAY L7742U THERMOSTAT 120VAC E NN e x HUMIDIFIER CONVENTIONAL 120 n NON COMMUNI 240VAC STEAM 2 CATING SYSTEM x HUMIDIFIER lt NEN icomfort Touch THERMOSTAT GREEN WHITE YELLOW RED RSBus OUTDOOR AIR SENSOR COMMUNICATING SYSTEM Maximum total length of all con nections on the RSBus is limited to 1500ft Wire gauge of RSBus wire is 18 KA PURPLE 24V IN JUMPE T oooo0 0000000 00000 icomfort ENABLED HUMIDITROL EDA M SL280DFV FURNACE In an icomfort by Lennox system neither furnace nor air handler trans former will have adequate VA to power 24V
24. LD SUPPLIED ACC WIRE USE COPPER CONDUCTORS ONLY DISCHARGE AND OUTDOOR AIR TERMINALS ARE FOR icomfort USE ONLY THERMOSTAT CONNECTIONS ARE FOR NON COMMUNICATING SYSTEM ONLY REFER TO icomfort INSTALLATION INSTRUCTIONS FOR COMMUNICATING SYSTEMS DH AND L TERMINALS ARE ONLY USED WITH icomfort THERMOSTAT 51 ROOM THERMOSTAT AN TWO STAGE WHITE RODGERS VALVE 43 WHITE RODGERS VALVE HEAT COOL R NOTE SEE INSTALLATION INSTRUCTIONS FOR PROCEDURE TO SET CORRECT BLOWER SPEED FOR SPECIFIC COOLING TONNAGE BEING APPLIED AND HEATING TEMPERATURE RISE REQUIRED TYPICAL SYSTEM SHOWN FOR 2 HEAT 2 COOL WITH A CONVENTIONAL THERMOSTAT SEE INSTALLATION INSTRUCTIONS FOR CONNECTIONS TO OTHER EQUIPMENT AND ACCESSORIES R If C R HM TERMINAL BOARD S51 DOOR INTERLOCK INTEGRATED CONTROL 11 A INDOOR EQUIPMENT A92 INTEGRATED CONTROL OUTDOOR EQUIPMENT 5102 5128 HIGH HEAT LOW HEAT PRESSURE SWITCH PRESSURE SWITCH FLAME SENSOR A OUTDOOR SENSOR DISCHARGE AIR SENSOR COMBUSTION AIR BLOWER MOTOR INDOOR BLOWER MOTOR 92 LENNOX INTEGRATED CONTROL SL280DF070V36A SL280DF090V48B HEATING UNITS GAS SL280DFO90V60C SL280DF110V60C J48 P48 2 HEAT 2 COOL WARNING ELECTRIC SHOCK HAZARD CAN CAUSE INJURY OR DEATH UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES NOTE IF ANY WIRE IN THIS APPLIANCE IS REPLACED IT MUST BE REPLACED WITH WIRE OF LIKE SIZE RAT
25. M Cutback Mode The variable speed motor has pre set speed and torque limiters to protect the motor from damage caused by operating outside of design parameters 0 to 0 8 W C total external static pressure Check filter and duct system To clear replace filter if needed or repair add duct Cleared after the current service demand is satisfied tions Alarm is just a warning The system will op erate but might not meet efficiency and capacity parameters Alarm will clear when commissioning is exited Cleared after commissioning is com plete E331 Global network connection Communication link problem For Future Use E334 Relay Y1 stuck on interated control Replace integrated control No 24 Volt output on Y1 of integrated control with non communicating Operation stopped Y1 relay Stage 1 failed Pilot E313 Indoor or outdoor unit capacity mismatch Communication only Incorrect indoor outdoor capacity code selected Check for proper configuring in installation instruc outdoor unit relay contacts did not close or the relay coil did not energize no input back to IFC chip Critical Alert Cleared after reset and Y 1 input sensed outdoor unit not close or the relay coil did not energize no in put back to IFC chip Critical Alert Cleared after E348 No 24 Volt output on Y2 of integrated control with non communicating Y2 relay Stage 2 failed Pilot relay contacts did reset and Y 1 input sensed
26. NNECTORS P48 5 Pin P49 4 Pin P48 5 Pin MOTOR with INTEGRATED CONTROLLER MOTOR with INTEGRATED J48 5 Pin CONTROLLER J49 4 Pin J49 4 Pin Control Connector PIN DESCRIPTION 2V INPUT 2 SERIAL DATA OUTPUT 3 SERIAL DATA INPUT 4 COMMON J48 5 Pin Line Voltage Connector DESCRIPTION JUMPER PIN I TO PIN 2 FOR 20VAC LINE INPUT ONLY sx l l 2 3 CHASSIS GROUND 4 5 P AC LINE AC LINE FIGURE 8 J48 Connector installed on motor P49 4 Pin 24v Transformer J49 Connector FIGURE 9 Page 22 C Heating Components 1 Ignitor The SureLight ignitor is made of durable silicon nitride Ig nitor longevity is enhanced by controlling voltage to the ig nitor The integrated control provides a regulated 120 volts to the ignitor for a consistent ignition and long ignitor life Ohm value should be 39 to 70 See figure 10 for ignitor location and figure 11 for ignitor check out NOTE The SL280DFV X furnace contains electronic components that are polarity sensitive Make sure that the furnace is wired correctly and is properly grounded 2 Flame Sensor A flame sensor is located on the left side of the burner sup port See figure 10 The sensor is tip protrudes into the flame envelope of th
27. OMPRESSOR amp FAN COOLING REQUEST IS ACTIVE INDOOR BLOWER LOW COOLING MODE AND HIGH COOLING MODE HAVE SPECIFIC ON OFF DE ENERGIZE INDOOR AND SPEED RAMPING PROFILES THE SPECIFIC PROFILE IS SELECTED USING THE BLOWER A DIP SWITCHES ON THE CONROL Page 46 Troubleshooting Continuous Fan Sequence of Operation CALL FOR FAN CALL FOR INDOOR BLOWER LOW SPEED MAINTAIN INDOOR BLOWER AT CONTINUOUS FAN REQUEST FOR COOLING ME GO TO CALL FOR COOLING CONTINUOUS FAN INDOOR BLOWER OFF DE ENERGIZE INDOOR BLOWER Page 47
28. OR TB83 R 24VAC I DATA HIGH CONNECTION I DATA LOW CONNECTION C 24VAC COMMON RS BUS INDOOR TB84 R 24VAC I DATA HIGH CONNECTION I DATA LOW CONNECTION C 24VAC COMMON 1 4 QUICK CONNECT TERMINALS HUM UNPOWERED NORMALLY OPEN DRY CONTACTS XMFR 120 VAC OUTPUT TO TRANSFORMER LI 120 VAC INPUT TO CONTROL ACC 120 VAC OUTPUT TO OPTIONAL ACCESSORY NEUTRALS 120 VAC NEUTRAL HS CAI NEUTRAL INDOOR BLOWER CONNECTOR 12 PIN LOW VOLTAGE CONNECTOR W915 Y1 TO Y2 2 STAGE COMPR W951RTOO HEAT PUMP W914 R TO DS DEHUM OR HARMONY NON COMMUNICATINGNG 24V TERMINALS THERMOSTAT CONNECTIONS TB1 DS DEHUMIDIFICATION SIGNAL W2 HEAT DEMAND FROM 2ND STAGE T STAT W1 HEAT DEMAND FROM 1ST STAGE T STAT R CLASS 2 VOLTAGE TO THERMOSTAT G MANUAL FAN FROM T STAT C THERMOSTAT SIGNAL GROUND CONNECTED TO TRANSFORMER GRD TR amp CHASIS GROUND GRD Y1 THERMOSTAT 1ST STAGE COOL SIGNAL Y2 THERMOSTAT 2ND STAGE COOL SIGNAL O THERMOSTAT SIGNAL TO HEAT PUMP REVERSING VALVE DH DEHUMIDIFICATION OUTPUT COMMUNICATING THERMOSTAT ONLY L USE ONLY WITH A COMMUNICATING THERMOSTAT AND A NON COMMUNICATING OUTDOOR UNIT FIGURE 4 Page 6 THERMOSTAT SELECTION THERMOSTAT THERMOSTAT TIMED STAGING SEE SW 2 90 SECOND HTG BLOWER OFF DELAY 60 SECOND HTG BLOWER OFF DELAY 120 SECOND HTG BLOWER OFF DELAY 180 SECOND HTG BLOWER OFF DELAY INCREASE
29. T OFF DELAY HARD LOCKOUT ERROR CODE HIGH PRESSUR FLASHES LOW SWITCH PRESSURE SWITC OPEN CLOSED WITHIN 120 BEFORE SECONDS INDUCER WAS INDUCER TO TURNED FLASHES SECONDS PRE PURGE 15 SECONDS WAIT BLOWER INTERPURGE 5 MINUTES OFF AFTER 5 1 ON 20 SECONDS 15 SECONDS ERROR CODE LLASHES HEAT FAN 1ST STAGE GAS VALVE ENERGIZED IGNITION TRIAL BEGINS 5 1 ON GAS VALVE DE ENERGIZED YES H S I OFF A WATCHGUARD LOCKOUT AUTOMATICALLY RESETS AFTER ONE HOUR INDOOR BLOWER ON 45 SEC A HARD LOCKOUT REQUIRES THERMOSTAT RESET OR CYCLING OF POWER TO RESET THE LOCKOUT LOW HEAT SPEED IN CASE HIGH SPEED INDUCER IS RUNNING AT THE TIME THE GAS VALVE GETS ENERGIZED 2ND STAGE GAS VALVE IS ENERGIZED INSTEAD OF 1ST STAGE 20 SECONDS AFTER FLAME IS SENSED INDUCER SWITCHES TO LOW SPEED AND GAS VALVE SWITCHES TO 1ST STAGE CALL FOR HEAT SATISFIED Page 43 Troubleshooting Heating Sequence of Operation Continued CALL FOR SECOND STAGE HEAT CALL FOR 2ND STAGE HEAT HIGH FIRE SINGLE STAGE 2 STAGE THERMOSTAT THERMOSTAT RECOGNITION DEL 2ND STAG 30 SECONDS ON DELAY ONLY FOR 1ST EXPIRED EXPIRED REQUEST FOR 2ND STAGE HEAT INDUCER SWITCHED TO HIGH SPEED PRESSURE SWITCH INDUCER SWITCHED 5 MINUTE DELAY CLOSED WITHIN 10 TO LOW SPEED ERROR CODE FLASHES 2ND STAGE GAS VALVE ENERGIZED INDOOR BLOWER ENERGIZED ON HIGH HEAT SPEED CALL FOR HEAT SATISFIED A SYSTEM WILL AL
30. TAT DISCHARGE AIR SENSOR icomfort Touch THERMOSTAT GREEN i WHITE YELLOW it R RED OUTDOOR AIR SENSOR OUTDOOR DISCHARGE IR SENSOR AIR SENSOR Al GREEN WHITE YELLOW RED i i R 00000 22000020 0209 icomfort ENABLED OUTDOOR AIR CONDITIONING OR HEAT PUMP UNIT INDOOR EQUIPMENT INDOOR EQUIPMENT 41 GREEN a NEUTER nt NON COMMUNICATING OUTDOOR AIR CONDITIONING UNIT 1 OR 2 STAGE l i R Y 2 OUTDOOR EQUIPMENT 222010000 0002 OUTDOOR EQUIPMENT YL 2 STG ONLY BL LSOM ONLY 4 CLIP ON BOARD LINK W915 Y1 TO Y2 FOR TWO STAGE OPERATION NOTE On communicating systems extra wires must terminate on the C RSBus terminal Use an additional wire and come off C terminal and wire nut all the extra wires together Termination on the outdoor control must match the indoor control icomfort Integrated Control Outdoor Unit icomfort Touch9 Page 36 Optional Accessories for use with any icomfort Touch System NOTE icomfort Touch THERMOSTAT SENSES HUMIDITY amp CONTROLS HUM CONTACTS TO CYCLE HUMIDIFIER 120V CONNECTIONS BASED ON DEMAND NO OTHER CONTROL OR HUMIDIS 74 TAT REQU
31. WAYS LIGHT ON LOW FIIRE EVEN IF 2ND STAGE HEAT IS IN PLACE A WHEN USED WITH A SINGLE STAGE THERMOSTAT SET SW1 TO THE ON POSITION IN DIP SWITCH S1 A IF THE HIGH FIRE PRESSURE SWITCH DOES NOT CLOSE WITHIN 5 ATTEMPTS THE SYSTEM WILL OPERATE AT LOW FIRE FOR THE REMAINDER OF THE CALL FOR HEAT REQUEST Page 44 Troubleshooting Heating Sequence of Operation Continued CALL FOR HEAT SATISFIED FIRST STAGE HEAT SECOND STAGE HEAT RUN MODE 1ST OR 2ND STAGE CALL FOR HEAT ALL INPUTS MONITORED LIMIT PRESSURE CALL FOR HEAT COOL FLAME LEVEL 2ND STAG CALL FOR HEAT SATISFIED 1ST STAGE CALL FOR HEAT SATISFIED INDOOR BLOWER OFF AFTER FIELD SELECTABLE OFF DELAY Page 45 Troubleshooting Cooling Sequence of Operation Continued CALL FOR COOLING 1ST STAGE COOLING REQUEST RECEIVED WAIT FOR COMPRESSOR TIMED OFF DELAY TO EXPIRE ENERGIZE 1ST STAGE COOLING CONTACTOR COMPRESSOR amp FAN INDOOR BLOWER 2 SECOND ON DELAY ENERGIZE INDOOR BLOWER LOW COOLING MODE MAINTAIN INDOOR BLOWER LOW COOLING MODE 2ND STAGE COOLING REQUEST YES ENERGIZE 2ND STAGE COOLING CONTACTOR COMPRESSOR amp FAN MAINTAIN INDOOR BLOWER HIGH COOLING MODE DE ENERGIZE 2ND STAGE COOLING CONTACTOR COMPRESSOR amp FAN ENERGIZE AND MAINTAIN INDOOR BLOWER AT LOW COOLING MODE DE ENERGIZE 1ST STAGE COOLING CONTACTOR A controt WILL NOT RESPOND TO A 2ND STAGE COOLING REQUEST UNLESS A 1ST STAGE C
32. aging blower gasket If gasket is damaged it must be replaced to prevent leakage Remove the collector box located behind the combus tion air inducer Be careful with the collector box gas ket If the gasket is damaged it must be replaced to prevent leakage Disconnect gas supply piping Remove the screw se N 1 curing the burner box cover and remove cover Re move the four screws securing the burner manifold as sembly to the vestibule panel and remove the assem bly from the unit Remove screws securing burner box and remove burner box Remove screws from both sides top and bottom of vestibule panel Remove heat exchanger It may be necessary to spread cabinet side to allow more room If so remove five screws from the left side or right side of cabinet See figure 18 SL280DFV BURNER C A I ASSEMBLY amp HEAT EXCHANGER REMOVAL orifice plate flue chase internal flue pipe combustion air inducer rollout switch ignitor burners pressure switch manifold and gas valve FIGURE 17 Page 32 collector box heat exchanger retention rings Cross over 10 11 16 17 18 19 20 21 Back wash using steam Begin from the burner opening on each clam Steam must not exceed 275 F To clean burners run a vacuum cleaner with a soft brush attachment over the face of burners Visually inspect in side the burners and crossovers for any blockage caused by foreign matter Remove
33. air conditioning units only is approximately 7096 of the same second stage COOL speed position Continuous Fan Only speed is selectable at 28 38 70 and 100 of the selected second stage cooling speed minimum 500 cfm Lennox Harmony III Zone Control Applications Minimum blower speed is 485 cfm Page 17 On Board Links Note In icomfort systems with a conventional outdoor unit non communicating the on board clippable links must be set to properly configure the system AWARNING Carefully review all configuration information pro vided Failure to properly set DIP switches jumpers and on board links can result in improper operation On Board Link W914 Dehum or Harmony R to DS On board link W914 is a clippable connection between ter minals R and DS on the integrated control W914 must be cut when the furnace is installed with either the Harmony IIl zone control or a thermostat which features humidity control If the link is left intact the PMW signal from the Har mony III control will be blocked and also lead to control damage Refer to table 12 for operation sequence in ap plications including SL280DFV a thermostat which fea tures humidity control and a single speed outdoor unit Table 13 gives the operation sequence in applications with a two speed outdoor unit On Board Link W951 Heat Pump R to O On board link W951 is a clippable connection between ter minals R and O on the integrated control W95
34. all DIP switch and clippable link settings are ignored For conventional ther mostats proceed with DIP switch and clippable link settings as outlined in the following Heating Operation DIP Switch Settings Switch 1 Thermostat Selection This unit may be used with either a single stage or two stage thermostat The thermostat selection is made using a DIP switch which must be properly positioned for the particular application The DIP switch is factory positioned for use with a two stage thermostat If a single stage thermostat is to be used the DIP switch must be repositioned a Select for two stage heating operation con trolled by a two stage heating thermostat factory set ting b Select ON for two stage heating operation con trolled by a single stage heating thermostat This set ting provides a timed delay before second stage heat is initiated Switch 2 Second Stage Delay Used with Single Stage Thermostat Only This switch is used to deter mine the second stage on delay when a single stage ther mostat is being used The switch is factory set in the OFF position which provides a 7 minute delay before second stage heat is initiated If the switch is toggled to the ON position it will provide a 12 minute delay before second stage heat is initiated This switch is only activated when the thermostat selector jumper is positioned for SINGLE stage thermostat use Switches 3 and 4 Blower Off Delay
35. and hold button Integrated control will display unit size code number for each furnace model for three seconds Page 38 UNIT SIZE CODE FURNACE MODEL SL280DF070V36A SL280DF090V48B SL280DF090V60C SL280DF110V60C Y When the correct unit size code is displayed release button Selected code will flash for 10 second period During that period press and hold push button for 5 seconds Integrated control will store code in memory and will automatically exit Program Unit Capacity Size Mode and reset If second period expires or push button is held less than five seconds control will automatically exit Program Capacity Size Mode and go into IDLE mode without storing unit size code If this happens programming function must be repeated Y Verify that the selected unit size code is correct stored non volatile memory by cycling the 24 volt power to the furnace control At 24 volt power up of the furnace control the 7 segment LED will display a unit size code If three horizontal bars display board does not recognize unit size code Programming function must be repeated FINISHED IX SL280 Field Wiring Applications With Conventional Thermostat Thermostat 1 Heat 1 Cool NOTE Use DIP switch 2 to set second stage heat ON delay OFF 7 minutes ON 12 minutes 1 Heat 2 Cool NOTE Use DIP switch 2 to set second stage heat ON delay OFF 7 mi
36. any blockage Figure 17 shows burner detail To clean the combustion air inducer visually inspect and using a wire brush clean where necessary Use com pressed air to clean off debris and any rust Reinstall heat exchanger in vestibule Replace the five screws in the cabinet from step 10 if removed Reinstall collector box combustion air assembly inter nal flue pipe and flue chase Seal with high tempera ture RTV Reinstall all screws to the collector box and combustion air inducer Failure to replace all screws may cause leaks Inspect gaskets for any damage and replace if necessary Reinstall burner box manifold assembly and burner box cover Reconnect all wires Reconnect top cap and vent pipe to combustion air in ducer outlet Reconnect gas supply piping Turn on power and gas supply to unit Set thermostat and check for proper operation Check all piping connections factory and field for gas leaks Use a leak detecting solution or other preferred means A CAUTION Some soaps used for leak detection are corrosive to certain metals Carefully rinse piping thoroughly af ter leak test has been completed Do not use matches flame other sources of ignition to check for gas leaks 22 If aleak is detected shut gas and electricity off and repair leak 23 Repeat steps 21 and 23 until no leaks are detected 24 Replace access panel Remove five screws if necessary either side of ca
37. ared after the correct match is detected following a reset Remove ther mostat from system while applying power and re programming E 203 Appliance capacity size is NOT programmed Invalid unit codes refer to No appliance capacity code selected Check for 202 Indoor blower motor mis match Indoor motor horsepower does not Incorrect appliance capacity code selected Check match unit capacity See Page 38 for proper configuring under Unit Size Codes for configuration flow chart See Page 38 proper configuring under Unit Size Codes for Fur nace on configuration guide or in installation instruc tions Critical Alert Cleared after valid unit code is read following a reset Remove thermostat from system while applying power and reprogramming 204 Gas valve mis wired Check gas valve operation and wiring Clears when repaired E 205 Gas valve control relay contact shorted Check wiring on control and gas valve If wiring is correct replace control Page 10 TABLE 5 Continued Code Diagnostic Codes Status of Equipment Action Required to Clear and Recover Gas valve second stage relay failure Furnace will operate on 151 stage for remainder of the heating demand Will clear after fault recovered If unable to operate 2nd stage replace control Hot surface ignitor sensed open Refer to troubleshooting SeePage 43 Measure resistance of hot surface ignitor Replace if open or not within specified range found
38. at start up COMBUSTION AIR PRESSURE SWITCH High Fire Switch Low Fire Switch TABLE 16 SL280DFV Unit Set oe Set Point Low Heat 49 os o m 085 028 II PLACEMENT AND INSTALLATION Make sure unit is installed in accordance with installation instructions and applicable codes Ill START UP A Preliminary and Seasonal Checks 1 Inspect electrical wiring both field and factory installed for loose connections Tighten as required 2 Check voltage at disconnect switch Voltage must be within range listed on the nameplate If not consult the power company and have voltage condition corrected before starting unit B Heating Start Up A WARNING Shock burn hazard SL280DFV units are equipped with a hot surface igni tion system Do not attempt to light manually 1 STOP Read the safety information at the beginning of this section 2 Set the thermostat to the lowest setting Page 26 3 Turn off all electrical power to the unit 4 This furnace is equipped with an ignition device which automatically lights the burners Do not try to light the burners by hand 5 Remove the upper access panel 6 Turn switch on gas valve to OFF Do not force See figure 13 or 14 Wait five minutes to clear out any gas If you then smell gas STOP Immediately call your gas supplier from a neighbor s phone Follow the gas suppliers instruc tions If you do not smell gas go to next step N
39. binet FIGURE 18 Page 33 VII Wiring and Sequence of Operation 120V ACC IF USED HUMIDIFIER n 51 ROOM THERMOSTAT WO QO O INTERLOCK SL280DFV Schematic Wiring Diagram 510 PRIMARY COMBUSTION AIR INDUCER MOTOR BURNERS ROLLOUT SWITCH FLAME SENSOR SEVEN A92 SEGMENT INTEGRATED 12345678 LED CONTROL 00000000 o 9101112131415 DIAGNOSTIC 0000000 78 SENSOR 4 DISCHARGE C_J OUTDOOR AIR BUTTON IGNITOR HIGH HEAT PRESSURE SWITCH 128 LOW HEAT PRESSURE SWITCH T 521 NEUTRALS 0 TRANSFORMER SECONDARY LIMIT 1 BLOWER SPEED CHART FACTORY SHIPPED SETTINGS UNIT HEAT COOL ADJUST rear rower 2 0707322 110V60C HUMIDIFIER AT IFC HUMIDIFIER AT IFC A CUT W914 JUMPER LABELED DEHUM OR HARMONY FROM DS TO R AT A92 CONTROL BOARD WHEN USED WITH Comfortsense Q 7000 THERMOSTAT A CUT W951 JUMPER FROM O TO R LABELED HEAT PUMP AT A92 CONTROL BOARD WHEN USED FOR DUAL FUEL APPLICATIONS A JUMPER W915 FROM Y1 TO Y2 IS FACTORY INSTALLED AT A92 CONTROL BOARD LEAVE IN FOR ONE STAGE COOL THERMOSTAT CUT JUMPER Y1 TO Y2 FOR TWO STAGE COOL THERMOSTAT A L5 USED ON 1HP ONLY THERMOSTAT HEAT ANTICIPATION SETTING HONEYWELL VALVE Character on segment LED w dot ON Circulator Motor Size Furnace Model TO R OR H ON CS7000 A DIP SWITCH FACTORY DEFAULT I FORA TWO STAGE THERMOSTAT A FIE
40. ce to maintain a cooler room thermostat setpoint Jumpers at indoor unit with a single stage outdoor unit With Condensing unit Cut W914 R to DS on SureLight board With Heat Pump Cut W914 R to DS amp W951 R to O on SureLight board ComfortSense 7000 thermostat to use for this application Y2081 4 heat 2 cool Dehumidification blower speed is 70 of COOL speed for all units In Precision mode ComfortSense 7000 thermostat will maintain room temperature up to 2 F 1 2 C cooler than room setting Page 18 TABLE 13 SL280DFV Non Communicating Thermostat with Humidity Control Feature and Two Stage Outdoor Unit OPERATING SEQUENCE SYSTEM DEMAND SYSTEM RESPONSE Thermostat Demand Relative Humidity System Step CALL FOR DEHUMIDIFICATION Normal Operation O 24 60 65 N Ts T 5 24 blower follow thermo ormal Operation stat demand ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING BASIC MODE only active on a Y1 thermostat demand O 24 60 65 ComfortSense 7000 Dehumidificat 5 7 60 65 Y2 de energizes D on a call for de humidi PRECISION MODE operates independent of a Y1 thermostat demand 24 60 65 Dehumidificat a 7 50 65 begins when humidity enumiditication 09 is greater than set point em 2 5m Oe ComfortSense 7000 thermostat will try to NE 5 o maintain room humidity
41. ct is opened For this reason it is necessary to wait at least 5 minutes after turning off power to the unit before attempt ing to service motor DANGER Disconnect power from unit and wait at least five minutes to allow to discharge before at tempting to service motor Failure to wait may cause personal injury or death Power Choke L13 A choke coil is used on SL280DFV 4 and 5 ton units equipped with 1 hp motors The choke is located on the blower housing and is used to suppress transient current spikes Page 21 Troubleshooting To verify motor operation see steps below 1 Remove J48 5 pin power plug from P48 on the mo tor 2 With the power on at the furnace and door switch de pressed use a test meter to verify 120V between pins 4 and 5 on J48 3 Reconnect J48 to P48 on the motor 4 Remove J49 4 pin low voltage connector from P49 on the motor 5 Using test jumpers apply 24V to pins 3 and 4 on P49 on the motor Note Do not apply 24V to pins 2 and 4 on P49 Doing so will cause permanent damage to the motor 6 Motor should run at 75 7 Test is complete Remove jumpers and reconnect plugs Another option is to use the TECMate PRO motor tester with the 16 to 4 pin adaptor The use of the TECMate PRO isolates the motor from the integrated control Follow the instructions provided with the kit If the motor runs do not replace BLOWER B3 HARNESS CONNECTORS BLOWER B3 HARNESS CO
42. d is displayed to exit the Error Code Recall mode Flame Signal Mode Select F from the menu to access the flame signal mode The integrated control will display the flame current on 7 segment LED in in micro amps uA Flame signal mode is exited after any of the following e Power is reset e Pressing and holding push button until 3 horizontal lines are displayed e 10 minutes after entering the flame sense mode Program Unit Capacity Size Mode After the P is selected by releasing the push button the integrated control will start flashing the P on display for 90 seconds If push button is pressed again and held during that time the control will start to display characters corre sponding to different variable speed furnace models for 3 seconds each While the wanted character model is dis played push button has to be released Selected option will flash display for 10 seconds and during that time push but ton has to be pressed and held for 5 seconds Once control accepts new setting it will store data in non volatile memory and reset itself If 10 seconds expires or push button is held less than 5 seconds control will exit field test mode and go into idle without changing programming the unit size Page 8 TABLE 5 Integrated Diagnostic Codes Status of Equipment I Diagnostic Codes Status of Equipment Action Required to Clear and Recover EN Idle mode Decimal blinks at 1 Hertz 0 5 second ON 0 5 second OFF
43. d not detected System shuts down Provide proper earth ground System resumes normal operation 5 seconds after fault recovered E 113 High line voltage Line Voltage High Voltage higher than nameplate rating Provide power voltage within proper range System resumes normal operation 5 seconds after fault recovered E 114 Line voltage frequency out of range No 60 Hertz Power Check voltage and line power frequency Correct voltage and frequency problems System resumes normal operation 5 seconds after fault recovered E 115 Low 24V Control will restart if the error recovers 24 Volt Power Low Range is 18 to 30 volts Check and correct voltage Check for additional power rob bing equipment connected to system May require installation of larger VA transformer to be installed in furnace air handler Clears after fault recovered E 116 High 24V 24 Volt Power High Range is 18 to 30 volts Check and correct voltage Check for proper line voltage 120V 240V etc to equipment Clears when con trol senses proper voltage E 117 Poor ground detected Warning only Provide proper grounding for unit Check for proper earth ground to the system Warning only will clear 30 seconds after fault recovered E 120 Unresponsive device Communication only Usually caused by delay in outdoor unit responding to indoor unit poling Recycle power Check all wir ing connections Cleared after unresponsive device responds to any i
44. e left most burner The sensor can be removed for service without removing any part of the burn ers During operation flame is sensed by current passed through the flame and sensing electrode The SureLight control allows the gas valve to remain open as long as flame signal is sensed To check flame sense signal use the push button found on the integrated control and go to Field Test Mode The menu will display the flame signal See table 14 for flame signal TABLE 14 Flame Signal in Microamps tow Drop Ou 3 Gas Valve The valve figure 13 or 14 is internally redundant to assure safety shut off If the gas valve must be replaced the same type valve must be used 24VAC terminals and gas control knob are located on the valve A wire harness connects the terminals from the gas valve to the electronic ignition control 24V applied to the termi nals energizes the valve Inlet and outlet pressure taps are located on the valve A regu lator adjustment screw is located on the valve LPG change over kits are available from Lennox Kits include burner orifices and a gas valve 4 Flame Rollout Switches S47 Flame rollout switch is a high temperature limit located on top of the burner box one on each side See figure 10 The limit is a N C SPST manual reset limit connected in series with the secondary limit S21 When S47 senses rollout the circuit breaks and the ignition control immediately stops ignition and closes the ga
45. ed E 270 Soft lockout Exceeded maximum number of retries No flame current Check for proper gas flow Ensure that ignitor is sensed lighting burner Check flame sensor current Clears when heat call finishes successfully Page 11 TABLE 5 Continued Diagnostic Codes Status of Equipment Action Required to Clear and Recover E271 Soft lockout Exceeded maximum number of retries Last retry failed due Check pressure inches w c of low pressure switch to the pressure switch opening closing on heat call Measure operating pressure inches w c Inspect vent and combustion air in ducer for correct operation and restriction Clears when heat call finishes successfully E 272 Soft lockout Exceeded maximum number of recycles Last recycle due Check operation of low pressure switch to see if it is to the pressure switch opening stuck closed on heat call Check pressure inches w c of high pressure switch closing on heat call Measure operating pressure inches w c Inspect vent and combustion air inducer for correct opera tion and restriction Clears when heat call finishes successfully to flame failure diagnostics or field installed mode Clean or replace sensor Measure voltage of neutral to ground to en sure good unit ground Clears when heat call finish 273 Soft lockout Exceeded maximum number of recycles Last recycle due Check micro amperes of flame sensor using control es successfully failed due to
46. ed 40VA with a 120V primary and a 24V sec ondary 2 Door Interlock Switch 551 An interlock switch rated 14A at 125VAC is wired in series with line voltage When the indoor blower access panel is removed the unit will shut down CONTROL BOX SL280DFV Transformer Circuit Breaker SureLight Integrated Control FIGURE 2 3 Circuit Breaker CB8 A 24V circuit breaker is also located in the control box The switch provides overcurrent protection to the trans former T1 The breaker is rated at 32V If the current exceeds this limit the breaker will trip and all unit opera tion will shutdown The breaker can be manually reset by pressing the button on the face See figure 3 FIGURE 3 A WARNING Shock hazard Disconnect power before servicing Integrated control is not field repairable If control is inoperable simply replace entire con trol Can cause injury or death Unsafe operation will result if repair is attempted 4 SureLight Integrated Control A92 Units are equipped with the icomfort enabled Sur eLight two stage variable speed integrated control This control is used with the icomfort Touch thermostat as part of a communicating comfort system The control can also operate with a non communicating conventional single or two stage thermostat The system consists of a ignition blower control figures 4 and 5 with control pin designa tions in tables 1 2 and 3 and ignitor figure 10
47. er From Unit 1 Disconnect Power 2 Remove internal flue pipe and chase 3 Remove Control Box 4 Remove Bolts 5 Unplug Motor Wires From Control Board Then Slide Out Front of Unit FIGURE 6 AWARNING During blower operation the ECM motor emits ener gy that may interfere with pacemaker operation In terference is reduced by both the sheet metal cabinet distance The motor communicates with the integrated control via a 2 way serial connection The motor receives all necessary functional parameters from the integrated control and does not rely on a factory program like traditional variable speed motors SL280DFV units use a three phase electronically controlled D C brushless motor controller converts single phase a c to three phase D C with a permanent magnet type rotor figure 7 Because this motor has a permanent magnet rotor it does not need brushes like conventional D C motors The stator windings are split into three poles which are electri cally connected to the controller This arrangement allows motor windings to turn on and off in sequence by the con troller A IMPORTANT Earlier ECM motors used on other Lennox furnace models are not interchangeable with motors used on the SL280DF furnace line A solid state controller is permanently attached to the motor The controller is primarily an A C to D C con verter Converted D C power is used to drive the motor The controller contains a micropr
48. ervice agency or the gas supplier Parts Identification Page 3 Unit Components Page 4 Il Installation Page 26 AWARN Start 26 Electric shock hazard Can cause injury or death Before attempting to perform IV Heating System Service Checks Page 28 any service or maintenance turn the xlii electrical power to unit OFF at discon V Typical Operating Characteristics Page 31 nect switch es Unit may have multiple VI Maintenance Page 31 power supplies VII Wiring and Sequence of Operation Page 34 VIII Program Unit Capacity Size Mode Page 38 A WARN NG T Sharp edges IX Field Wiring and Jumper Settings Page 39 Be careful when servicing unit to avoid sharp edges X Troubleshooting Flow Chart Page 43 which may result in personal injury Publications Page 1 2011 Lennox Industries Inc SPECIFICATIONS Gas Model No SL280DF070V36A SL280DF090V48B SL280DF090V60C SL280DF110V60C cat M 1 AFUE 80 80 80 80 High Input Btuh 66 000 88 000 88 000 110 000 Fire Output Btuh 52 000 69 000 70 000 87 000 Temperature rise range F 35 65 35 65 35 65 35 65 Gas Manifold Pressure in w g 3 5 10 0 3 5 10 0 3 5 10 0 3 5 10 0 Nat
49. h troubleshooting See Page 43 closing on heat call Measure operating pressure inches w c Inspect vent and combustion air in ducer for correct operation and restriction Re sumes normal operation after fault is cleared Combustion air inducer calibration failure Unable to perform pressure switch calibration Check vent system and pressure switch wiring con nections Resumes normal operation after fault is cleared Ignition on high fire IFC switched to high fire ignition because low fire pressure switch did not close in allowed time No action is needed Low flame current Run mode Refer to troubleshooting See Page 43 Check micro amperes of flame sensor using control diagnostics or field installed mode Clean or replace sensor Measure voltage of neutral to ground to en sure good unit ground Alert clears after current heat call has been completed Flame sensed out of sequence Flame still present Shut off gas Check for gas valve leak Replace if necessary Alert clears when fault is recovered Limit switch circuit open Refer to troubleshooting See Page 43 Check for proper firing rate on furnace Ensure there is no blockage in heater Check for proper air flow If limit not closed within 3 minutes unit will go into 1 hour soft lockout Resumes normal operation after fault is cleared Discharge air temperature too high gas heat only Check temperature rise air flow and input rate Cleared when heat call is finish
50. in IOM Resumes normal operation after fault is cleared Low pressure switch failed open Check pressure inches w c of low pressure switch closing on heat call Measure operating pressure inches w c Inspect vent and combustion air in ducer for correct operation and restriction Re sumes normal operation after fault is cleared Low pressure switch failed closed Refer to troubleshooting See Check operation of low pressure switch to see if it is Page 43 stuck closed on heat call longer than 150 seconds Measure operating pressure inches w c Inspect vent and combustion air inducer for correct opera tion and restriction Resumes normal operation after fault is cleared High pressure switch failed open Refer to troubleshooting See Check pressure inches w c of high pressure Page 43 Switch closing on heat call Measure operating pres sure inches w c Inspect vent and combustion air inducer for correct operation and restriction Re sumes normal operation after fault is cleared E 206 High pressure switch failed closed Refer to troubleshooting See Check operation of high pressure switch closing on E 250 Page 43 heat call Measure operating pressure inches w c Inspect vent and combustion air inducer for correct operation and restriction Resumes normal opera tion after fault is cleared Low pressure switch open during trial for ignition or run mode Refer to Check pressure inches w c of low pressure switc
51. ing units only is approximately 70 of the same second stage COOL speed position Continuous Fan Only speed is selectable at 28 38 70 and 100 of the selected second stage cooling speed minimum 500 cfm Lennox Harmony III Zone Control Applications Minimum blower speed is 455 cfm Page 16 BLOWER DATA SL280DF090V60C BLOWER PERFORMANCE less filter 0 through 0 8 in w g Heating and 0 through 1 0 in w g Cooling External Static Pressure Range Heating Speed HEATING DIP Switch First Stage Heating Speed cfm Second Stage Heating Speed cfm Settings 24 1540 1695 18 1465 1615 12 1390 1530 6 1320 1450 Factory Default 1245 1365 6 1170 1285 12 1095 1205 18 1020 1120 COOLING 1 Cooling Speed First Stage Cooling Speed cfm Second Stage Cooling Speed cfm po Low Medium Low Medium High High Low Medium Low Medium High High 1125 1250 1400 1590 1585 1770 2000 2275 Factory Default 1020 1135 1285 1445 1420 1610 1845 2 050 900 1005 1155 1280 1305 1395 1645 1875 1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control Refer to Installation Instructions for specific DIP Switch Settings Factory default setting NOTES The effect of s atic pressure is included in air volumes shown First stage HEAT is approximately 91 of the same second stage HEAT First stage COOL tw
52. integrated control automatically ramps down to 7096 of the second stage cfm for first stage cfm Refer to blower tables for corresponding cfm values TABLE 7 Cooling Mode Blower Speeds Speed Switch5 Switche p low O O Switches 7 and 8 Cooling Blower Speed Adjustment The unit is shipped from the factory with the dip switches positioned for NORMAL no adjustment The dip switches may be positioned to adjust the blower speed by 10 or Page 14 10 to better suit the application Table 8 below provides blower speed adjustments that will result from different switch settings Refer to blower tables for corresponding cfm values TABLE 8 Cooling Blower Speed Adjustment Adjustment Switch7 Switch8 10 aprox Of Switches 9 and 10 Cooling Mode Blower Speed Ramping Blower speed ramping may be used to en hance dehumidification performance The switches are factory set at option A which has the greatest effect on de humidification performance Table 9 provides the cooling mode blower speed ramping options that will result from different switch settings The cooling mode blower speed ramping options are detailed below NOTE The off portion of the selected ramp profile also ap plies during heat pump operation in dual fuel applications TABLE 9 Cooling Mode Blower Speed Ramping RampingOption Switch 9 Switch 10 B of O Ramping Opti
53. inutes Compressor runs less than 3 minutes to satisfy a secutive normal run cycles or power reset less than 4 minutes short bearings are seized excessive liquid refrig erant etc Clears the error after 4 consecutive nor E404 LSOM Compressor rotor locked Compressor short cycling Running Compressor rotor locked up due to run capacitor mal run cycles or after power reset tion open fuse etc Clears the error after 1 nor mal compressor run cycle E405 LSOM Compressor open circuit Compressor circuit open due to power disconnec Page 13 TABLE 5 Continued Diagnostic Codes Status of Equipment Action Required to Clear and Recover LSOM Compressor open start circuit Required amount of current is not passing through Start current transformer Clears the error after cur rent is sensed in START sensor or after power re set LSOM Compressor open run circuit Required amount of current is not passing through Run current transformer Clears the error after cur rent is sensed in RUN sensor or 1 normal compres sor run cycle or after power reset after 1 normal compressor run cycle or after power 408 LSOM Compressor contactor is welded Compressor runs continuously Clears the error reset LSOM Compressor low voltage DIP Switch Settings NOTE All icomfort settings are set at the icomfort Touch thermostat See icomfort installation instruction In icomfort communication system
54. ition for use with a two stage thermostat Move the DIP switch to ON for use with a single stage thermostat While in the single stage thermostat mode single DIP switch setting the burners will always fire on first stage heat The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed After a factory default 10 minute recognition period the unit will switch to second stage heat While in the two stage ther mostat mode two DIP switch setting the burners will fire on first stage heat The combustion air inducer will operate on low speed and indoor blower will operate on low heat speed The unit will switch to second stage heat on call from the indoor thermostat If there is a simultaneous call for first and second stage heat the unit will fire an first stage heat and switch to second stage heat after 30 seconds of operation See Sequence of Operation flow charts in the back of this manual for more detail Page 5 TABLE 1 SureLight Control 5 Pin Terminal Designation oe BENE TABLE 2 SureLight Control 12 Pin Terminal Designation INTEGRATED CONTROL 7 SEGMENT LED FLAME SENSE DIAGNOSTIC PUSH BUTTON DIP SWITCHES OUTDOOR AIR__ SENSOR TERMINALS DISCHARGE AIR SENSOR TERMINALS TB83 COMMUNICATING OUTDOOR EQUIPMENT TB84 COMMUNICATING INDOOR THERMOSTAT RS BUS LINK TB82 future use I DATA HIGH CONNECTION DATA LOW CONNECTION RS BUS OUTDO
55. let run for 5 minutes to allow for steady state conditions 3 After allowing unit to stabilize for 5 minutes record manifold pressure and compare to value given in table 19 4 f necessary make adjustments Figures 13 and 14 show location of high fire adjustment screw 5 If an adjustment is made on high fire re check man ifold pressure on low fire Do not adjust low fire man ifold pressure f low fire manifold pressure is more than 1 2 above or below value specified in table 19 replace valve IMPORTANT For safety shut unit off and remove manometer as soon as an accurate reading has been obtained Take care to replace pressure tap plug Page 28 F Proper Gas Flow Approximate Furnace should operate at least 5 minutes before check ing gas flow Determine time in seconds for two revolu tions of gas through the meter Two revolutions assures a more accurate time Divide by two and compare to time in table 17 below If manifold pressure matches table 19 and rate is incorrect check gas orifices for proper size and restriction NOTE To obtain accurate reading shut off all other gas appliances connected to meter TABLE 17 GAS METER CLOCKING CHART Seconds for One Revolution si280DF Nawa P Unit 2 cu ft DIAL ws T5 20 400 70 272 me pw ms m s w m Natural 1000 btu cu ft LP 2500 btu cu ft Page 29 A IMPORTANT For safety shut unit off and remove manome
56. ll filters are installed external to the unit Filters should be inspected monthly Clean or replace the filters when neces sary to ensure that the furnace operates properly Replace ment filters must be rated for high velocity airflow C Flue and Chimney Check the flue pipe chimney and all connections for tight ness and to make sure there is no blockage A Disconnected Vent warning sticker should be attached to a visible area of the plenum near the vent pipe If the sticker is not legible or missing order kit 66W04 for re placement stickers D Electrical 1 Check all wiring for loose connections 2 Check for the correct voltage at the furnace furnace operating Correct voltage is 120VAC 10 Check amp draw on the blower motor with inner blow er access panel in place Unit Nameplate Actual E Heat Exchanger and Burners Cleaning the Heat Exchanger and Burners NOTE Use papers or protective covering in front of the fur nace during cleaning 1 Turn off both electrical and gas power supplies to fur nace 2 Remove flue pipe top cap flue chase and internal flue pipe assembly from the unit 3 Label the wires from gas valve rollout switches prima ry limit switch and make up box then disconnect them 9 1 4 6 burner box assembly Remove the screws that secure the combustion air in ducer pressure switch assembly to the collector box Carefully remove the combustion air inducer to avoid dam
57. mbustion blower bearings wiring and amps Replace if does not operate or does not meet performance standards Clears after inducer current is sensed to be in range after the ignition following the soft lockout or reset tripped on internal protector Check motor bearings and amps Replace if necessary Cleared after 295 Indoor blower motor temperature is too high Indoor blower motor over temperature motor blower demand is satisfied out of range resistance charts in installation instructions Re place sensor if necessary Cleared in Communicat ing mode 30 seconds after fault recovered In Non Communicating mode Cleared after the current E310 Discharge error temperature sensor failure Only shown if shorted or Compare outdoor sensor resistance to temperature heat call is completed seconds to match available CFM Check filter and duct system To clear replace filter if needed or re pair add duct 2 stage controls will reduce firing rate to 15 stage Clears when heat call finishes success fully E311 Heat rate reduced to match indoor blower air flow Warning Only Furnace blower in cutback mode due to restricted airflow Reduce firing rate every 60 Page 12 TABLE 5 Continued Diagnostic Codes Status of Equipment Action Required to Clear and Recover E312 Restricted air flow in cooling or continuous fan mode is lower than cfm Warning Only Restricted airflow Indoor blower is setting running at a reduced CF
58. n this manual on the unit wiring dia gram and on blower B3 refer to blower cfm regardless of mo tor rpm Initial Power Up When line voltage is applied to B3 there will be a large inrush of power lasting less than 1 4 second This inrush charges a bank of DC filter capacitors inside the controller If the discon nect switch is bounced when the disconnect is closed the dis connect contacts may become welded Try not to bounce the disconnect switch when applying power to the unit Page 20 Motor Start Up When B3 begins start up the motor gently vibrates back and forth for a moment This is normal During this time the elec tronic controller is determining the exact position of the rotor Once the motor begins turning the controller slowly eases the motor up to speed this is called soft start The motor may take as long as 10 15 seconds to reach full speed If the motor does not reach 200 rpm within 13 seconds the motor shuts down Then the motor will immediately attempt a re start The shutdown feature provides protection in case of a frozen bearing or blocked blower wheel The motor may at tempt to start eight times If the motor does not start after the eighth try the controller locks out Reset controller by momen tarily turning off power to unit The DC filter capacitors inside the controller are connected electrically to the motor supply wires The capacitors take approximately 5 minutes to discharge when the disconne
59. nquiry Page 9 TABLE 5 Continued Diagnostic Codes Status of Equipment Action Required to Clear and Recover Active communicating thermostat signal missing for more than 3 min Equipment lost communication with the thermostat utes Check four wiring connections ohm wires and cycle power at the thermostat Alert stops all services and waits for heartbeat message from thermostat sub net controller Cleared after valid thermostat sub net controller message is received E 125 Control failed self check internal error failed hardware Will restart if Hardware problem on the control Cycle power on error control Replace if problem prevents service and is recovers Integrated control not communicating Covers hardware errors persistent Critical alert Cleared 300 seconds after flame sense circuit faults pin shorts etc fault recovered E 126 Control internal communication problem Hardware problem on the control Cycle power on control Replace if problem prevents service and is persistent Cleared 300 seconds after fault recov ered E 131 Corrupted control parameters Verify configuration of system Communi Reconfigure the system Replace control if heating cating only or cooling is not available Only applicable in the communicating mode not in startup Exit from Com missioning and Execute Set Factory Default mode Control will still operate on default parameter set tings E 180 Outdoor air temperat
60. nutes ON 12 minutes 1 Heat 2 Cool with t stat with humidity control NOTE Use DIP switch 2 to set second stage heat ON delay OFF 7 minutes ON 12 minutes DIP Switch Settings and On Board Links See figure 4 DIP Switch 1 Thermostat Heating Stages Not required on all units On Board Links Must Be Cut To Select System Options DO NOT CUT ANY ON BOARD LINKS SELE ON 2 bins E CUT ON BOARD LINK 951 W915 BME 2 STAGE COMPR HARMONY CUT ON BOARD LINK W915 2 STAGE COMPR CUT ON BOARD LINK W914 DEHUM OR HARMONY Page 39 Wiring Connections FURNACE TERM STRIP 9 6 6 6 OUTDOOR UNIT 51 FURNACE T STAT TERM STRIP OUTDOOR UNIT FURNACE TERM STRIP OUTDOOR UNIT SL280 Field Wiring Applications With Conventional Thermostat Continued DIP Switch Settings and On Board Links See figure 4 DIP Switch 1 Thermostat Thermostat Wiring Connections Heating y pions Stages 2 Heat 2 Cool S1 FURNACE OUTDOOR 9 CUT ON BOARD LINK 795 So m m C o Bot 2410 gt p D0 m 5 0 2 Hea
61. o stage air conditioning units only is approximately 7096 of the same second stage COOL speed position Continuous Fan Only speed is selectable at 28 38 70 and 100 of the selected second stage cooling speed minimum 500 cfm Lennox Harmony III Zone Control Applications Minimum blower speed is 480 cfm SL280DF110V60C BLOWER PERFORMANCE less filter 0 through 0 8 in w g Heating and 0 through 1 0 in w g Cooling External Static Pressure Range Heating Speed HEATING DIP Switch First Stage Heating Speed cfm Second Stage Heating Speed cfm Settings 24 1645 1810 18 1565 1720 12 1485 1635 6 1405 1545 Factory Default 1325 1460 6 1245 1370 12 1170 1285 18 1090 1195 COOLING 1 Cooling Speed First Stage Cooling Speed cfm Second Stage Cooling Speed cfm prd Low Medium Low Medium High High Low Medium Low Medium High High 1075 1225 1370 1530 1500 1755 1915 2120 Factory Default 945 1120 1230 1385 1360 1585 1770 1960 880 985 1135 1235 1225 1405 1595 1760 1 Cooling and heating speeds are based on a combination of DIP switch settings on the furnace control Refer to Installation Instructions for specific DIP Switch Settings Factory default setting NOTES The effect of s atic pressure is included in air volumes shown First stage HEAT is approximately 91 of the same second stage HEAT First stage COOL two stage
62. ocessor which moni tors varying conditions inside the motor Such as motor workload BLOWER MOTOR COMPONENTS STATOR WINDINGS BEARING 9 lt SN FIGURE 7 The controller uses sensing devices to sense what position the rotor is in at any given time By sensing the position of the rotor and then switching the motor windings on and off in se quence the rotor shaft turns the blower All SL280DFV blower motors use single phase power An external run capacitor is not used The motor uses permanently lubricated ball type bearings Internal Operation The motor is controlled via serial communication between the integrated control on the furnace and the controller at tached to the motor shell The messages sent back and forth between the two controls serve to communicate rota tional direction demand motor size current draw torque and rpm among other variables Motor rpm is continually adjusted internally to maintain constant static pressure against the blower wheel The control ler monitors the static work load on the motor and motor amp draw to determine the amount of rpm adjustment Blower rpm may be adjusted any amount in order to maintain a constant cfm as shown in Blower Ratings Tables The cfm remains rel atively stable over a broad range of static pressure Since the blower constantly adjusts rpm to maintain a specified cfm mo tor rpm is not rated Hence the terms cool speed heat speed or speed tap i
63. on A Factory Selection e Motor runs at 50 for 30 seconds e Motor then runs at 8296 for approximately 7 1 2 minu tes e f demand has not been satisfied after 7 1 2 minutes motor runs at 10096 until demand is satisfied e Once demand is met motor runs at 50 for 30 sec onds then ramps down to stop 7 1 2 MIN 82 CFM 100 OFF CFM T OFF 1 2 MIN 50 CFM COMPRESSOR DEMAN Ramping Option B e Motor runs at 82 for approximately 7 1 2 minutes If demand has not been satisfied after 7 1 2 minutes motor runs at 100 until demand is satisfied e Once demand is met motor ramps down to stop 7 4 2 MIN E 100 gt OFF 82 CFM OFF COMPRESSOR DEMAND Page 15 Ramping Option C Motor runs at 100 until demand is satisfied e Once demand is met motor runs at 100 for 45 sec onds then ramps down to stop 100 r 100 OFF Casos 4 DEMAND 45 SEC Ramping Option D Motor runs at 100 until demand is satisfied e Once demand is met motor ramps down to stop 10096 CFM GEE COMPRESSOR OFF DEMAND Switches 11 12 and 13 Heating Mode Blower Speed The switches are factory set to the OFF position which pro vides factory default heat speed Refer to table 10 for switches 11 12 and 13 that provided the corresponding in creases or decrease to both high and low heat demand TABLE 10 Heating Mode Blower Speeds Heat Speed Increase 24
64. ond pre purge the high fire pressure switch will close and the unit will begin operation on high fire After 20 seconds of high fire operation the unit will switch to low fire SureLight control begins 20 second ignitor warm up period Gas valve opens on first stage for a 4 second trial for ignition Ignitor stays energized during the trial or until flame sensed Flame is sensed gas valve remains on first stage heat ignitor de energizes After 45 second delay indoor blower B3 is energized on low heat speed A 10 minute factory set or 15 minute field set second stage heat delay period begins After the delay the combustion air inducer ramps up to high heat speed 5102 high heat prove switch closes and the gas valve energizes second stage heat B3 indoor blower ramps up to high heat speed icomfort Touch Thermostat with SL280DFV icomfort Touch Thermostat with SL280DFV and Non Communicating Outdoor Unit and icomfort ENABLED Outdoor Unit icomfort Touch Thermostat icomfort Touch Thermostat icomfort Enabled SL280DFV Indoor Furnace icomfort Enabled SL280DFV Indoor Furnace Non Communicating Outdoor Air Conditioner icomfort Enabled Outdoor Air Conditioner or Heat Pump icomfort ENABLED icomfort SL280DFV ENABLED FURNACE OPTIONAL NACL DISCHARGE AIR SENSOR om OPTIONAL DISCHARGE AIR SENSOR TN OPTIONAL Bc OUTDOOR OPTIONAL i AIR SENSOR OUTDOOR AIR SENSOR Ce icomfort Touch THERMOS
65. placed 7 Secondary Limit Controls 521 The secondary limit S21 is located in the blower compart ment See figure 6 When excess heat is sensed in the blower compartment the limit will open If the limit is open the furnace control energizes the supply air blower and closes the gas valve The limit automatically resets when unit temperature re turns to normal The switch must reset within three minutes or the SureLight control will go into Watch guard for one hour The switch is factory set and cannot be adjusted Page 23 SL280DFV HEATING COMPONENTS Rollout Switch Ignitor lt Screw remove and panel will swing open and off FIGURE 10 Page 24 SL280DF Ignitor Check Out Multi Meter set to ohms Test 1 Di 534 Integrated Control Board Remove 5 pin plug from control petal Check ohms reading across terminals 1and 5 Ohm value should be between 39 70 Multi Meter set to ohms Test 2 Seperate the 2 pin jack plug near the manifold and check resistance of the ignitor If the reading is correct then then there is a problem with the wiring between the jack plug and control If the reading is not correct the issue is the ignitor Integrated C Detai ental Multi Meter set to VAC Integrated Control Board Detail Test 3 Insert meter probes into the terminals 1 and 5 Use small diameter probes in order to not damage plug Check voltage during 20 second warm up period Voltage
66. pply gas pipe must not be smaller than unit gas connection Compounds used on gas piping threaded joints should be resistant to action of liquefied petroleum gases C Testing Gas Piping A IMPORTANT In case emergency shutdown is required turn off the main shut off valve and disconnect the main power to unit These controls should be properly labeled by the installer When pressure testing gas lines the gas valve must be dis connected and isolated Gas valves can be damaged if subjected to more than 0 5 psig 14 W C See figure 15 If the pressure is equal to or less than 0 5psig 14 W C use the manual shut off valve before pressure testing to isolate furnace from gas supply GAS PIPING TEST PROCEDURE MANUAL MAIN SHUT OFF VALVE Q WILL NOT HOLD TEST PRESSURE IN EXCESS OF 0 5 PSIG 14 W C 1 8 NPT PLUG 11 DES GAS VALVE CAP FIELD PROVIDED LINE PRESSURE TAP FIGURE 15 When checking piping connections for gas leaks use pre ferred means Kitchen detergents can cause harmful corro sion on various metals used in gas piping Use of a specialty Gas Leak Detector is strongly recommended It is available through Lennox under part number 31B2001 See Corp 8411 L10 for further details Do not use matches candles flame or any other source of ignition to check for gas leaks D Testing Gas Supply Pre
67. rgized on low first stage Page 4 heat speed When the differential in the prove switch is great enough the prove switch closes and a 15 second pre purge begins NOTE During abnormal conditions such as low supply voltage or low outdoor temperatures and the low fire pres sure switch does not close the combustion air inducer will switch to high fire After a 15 second pre purge the high fire pressure switch will close and the unit will begin operation on high fire After 10 to 20 seconds of high fire operation the unit will switch to low fire After the 15 second pre purge period the SureLight ignitor warms up for 20 seconds after which the gas valve opens for a 4 second trial for ignition The ignitor energizes during the trial until flame is sensed If ignition is not proved during the 4 second period the control will try four more times with an inter purge and warm up time between trials of 35 sec onds After a total of five trials for ignition including the ini tial trial the control goes into Watchguard Flame Failure mode After a 60 minute reset period the control will begin the ignition sequence again Two Stage Operation Thermostat Selection DIP Switch The control can be utilized in two modes SINGLE STAGE thermostat or TWO STAGE thermostat The thermostat selection is made using a DIP switch and must be posi tioned for the particular application DIP switch 1 labeled T STAT HEAT STAGE is factory set in the OFF pos
68. ropane gas changeover kit is necessary to convert this unit Refer to the changeover kit installation instruction for the conversion procedure NOTE Units may be installed at altitudes up to 4500 ft above sea level without modifications TABLE 20 High Altitude Pressure Switch High Altitude Pressure Switch Kit 0 4500 ft 4501 7500 ft 7501 10 000 ft No Change 69W56 73W36 No Change 69W56 73W35 TABLE 21 Honeywell Gas Valve Conversion Kits No Change No Change 73W36 LP Propane Natural Gas to to LP Propane Kit Natural Gas Kit 7501 7501 10 000f 9 7500ft 49 O00 ft 0 7500 ft 73W37 51W02 73W38 69W79 090 73W37 51W02 73W38 69W79 73W37 51W02 73W38 69W79 High Altitude Natural Gas Orifice Kit TABLE 22 White Rodgers Gas Valve Conversion Kits LP Propane Natural Gas to to LP Propane Kit Natural Gas Kit High Altitude Natural Gas Unit Orifice Kit Input 7501 7501 10 000 t 0 7500 40 000 0 7500 ft 73W37 77W07 77W11 77W09 090 73W37 77W07 77W11 77W09 73W37 77W07 77W11 77W09 Page 30 V TYPICAL OPERATING CHARACTERISTICS A Blower Operation and Adjustment When the thermostat is set to FAN ON the indoor blower will run continuously at approximately 38 of the second stage cooling speed when there is no cool ing or heating demand When the SL280DFV is running on high fire or low fire low fire is 91 of high fire the indoor blower will run on the heating speed
69. s valve Rollout can be caused by a blocked heat exchanger flue or lack of combustion air The switch is factory set to trip open at 210 F and cannot be adjusted The switch can be manually reset To manually re set a tripped switch push the reset button located on the con trol 5 Burners All units use inshot burners Burners are factory set and re quire no adjustment Always operate the unit with the burner box front panel in place Each burner uses an orifice see table 19 for orifice size that is precisely matched to the burn er input Burners can be removed as a one piece assembly for service If burner assembly has been removed it is critical to align center of each burner to the center of the clamshell when re installing See more detail in Section VI MAINTE NANCE sub section E Heat Exchanger and Burners 6 Primary Limit Control S10 The primary limit S10 is located in the heating vestibule pan el When excess heat is sensed in the heat exchanger the limit will open If the limit is open the furnace control energizes the supply air blower and closes the gas valve The limit auto matically resets when unit temperature returns to normal The switch must reset within three minutes or the SureLight control will go into Watch guard for one hour The switch is factory set and cannot be adjusted The switch may have a different set point for each unit model number See Lennox Repair Parts Handbook if limit switch must be re
70. ssure White Rodgers Gas Valve An inlet post located on the gas valve provides access to the supply pressure See figure 13 Back out the 3 32 hex screw one turn connect a piece of 5 16 tubing and connect to a manometer to measure supply pressure See table 19 for supply line pressure Honeywell Gas Valve A threaded plug on the inlet side of the gas valve provides access to the supply pressure tap Remove the threaded plug install a field provided barbed fitting and connect a manometer to measure supply pressure See table 19 for supply line pressure Replace the threaded plug after mea surements have been taken E Check Manifold Pressure After line pressure has been checked and adjusted check manifold pressure Move pressure gauge to outlet pres sure tap located on unit gas valve GV1 Checks of man ifold pressure are made as verification of proper regulator ad justment Manifold pressure can be measured at any time the gas valve is open and is supplying gas to the unit See table 19 for normal operating manifold pressure IMPORTANT For safety connect a shut off valve between the manometer and the gas tap to permit shut off of gas pressure to the manometer The gas valve is factory set and should not require adjust ment All gas valves are factory regulated Manifold Adjustment Procedure 1 Connect test gauge to manifold pressure post figure 13 or tap figure 14 on gas valve 2 Ignite unit on high fire and
71. t 2 Cool FURNACE OUTDOOR with t stat with TERM STRIP UNIT W915 humidity control 2 Heat 1 Cool FURNACE OUTDOOR with t stat with TERM STRIP UNIT humidity control CUT ON BOARD LINK w914 2 Heat 1 Cool S1 FURNACE OUTDOOR T STAT TERM STRIP UNIT ON BOARD LINKS Cass sss 4 bl bl Ub b b aaa NN Not required on all units Page 40 SL280 Field Wiring Applications With Conventional Thermostat Continued DIP Switch 1 Thermostat Thermostat On Board Links Must Be Cut To Select Wiring Connections Heating System Options Stages Dual Fuel FURNACE HEAT PUMP TERM STRIP Single Stage Heat Pump CUT ON BOARD LINK ComfortSense 7000 L7742U thermostat w dual fuel capa bilities Capable of 2 stage gas heat control loutdoor sensor Dual Fuel SERM STRIP HEAT PUMP Two Stage CUT ON BOARD LINK Heat Pump W915 2 STAGE ComfortSense COMPE 7000 L7742U thermostat w CUT ON BOARD LINK dual fuel capa W951 e bilities HEAT Capable of 2 PUMPE stage gas heat IEJEJEJEJ control Connect W1 to W1 ONLY if using defrost tempering kit 67M41 NOTE Do NOT make a wire connection between the room thermostat L terminal and the L terminal of the SL280 integrated control Page 41 SL280 Field Wiring Applications With Conventional Thermostat Continued DIP Switch Settings and On Board Links figure 4 Thermostat Dual
72. ter as soon as an accurate reading has been obtained Take care to replace pressure tap plug G Proper Combustion Furnace should operate minimum 15 minutes with correct manifold pressure and gas flow rate before checking com bustion See sections E and F Take combustion sample beyond the flue outlet and compare to the table below The maximum carbon monoxide reading should not exceed 50 ppm TABLE 18 High Fire 6 0 7 4 6 9 8 4 48 60 57 70 carbon monoxide reading should not exceed 50 ppm H High Altitude The manifold pressure gas orifice and pressure switch may require adjustment or replacement to ensure proper operation at higher altitudes See table 19 for manifold pressures table 20 for pressure switch kits and table 22 or 21 for gas conversion kits Table 19 Manifold Pressure Settings Manifold Pressure in wg 0 4500 ft Orifice Size 7501 10 000 ft Orifice Size 0 7500 ft Natural 063 055 1 7 LP propane 039 037 4 9 0 Natural 110 1 This is the only permissible derate for these units Natural gas high altitude orifice kit required Manifold Pressure in wg 4501 7500 ft Manifold Pressure in wg 7501 10 000 ft 2 Supply Line Pressure in w g 3 5 1 6 3 4 1 7 3 5 4 5 13 0 10 0 4 9 10 0 4 9 10 0 11 0 13 0 070 cm 07 s to sos r Go 063 055 1 7 3 5 1 5 3 2 1 7 3 5 4 5 13 0 3 A natural to L P p
73. the limit circuit opening or limit remained open longer than rate and air flow Check for blockage Clears when 3 minutes heat call finishes successfully E 275 Soft lockout Flame sensed out of sequence Flame signal is gone Shut off gas Check for gas valve leak 1 hour soft lockout Clears when flame has been proven stable Watchguard calibration failure Unable to perform pressure switch calibration Check vent system and pressure switch wiring con nections 1 hour soft lockout Clears when calibra tion has finished successfully 290 Ignitor circuit fault Failed ignitor or triggering circuitry Measure resistance of hot surface ignitor Replace if E 274 Soft lockout Exceeded maximum number of recycles Last recycle Shut down system 1 hour soft lockout Check firing open or not within specifications 1 hour soft lock out Clears when flame has been proven stable blower performance 1 hour soft lockout Cleared E 291 Heat air flow restricted below the minimum Check for dirty filter and air flow restriction Check when heat call finishes successfully bearings ing stuck wheel etc Replace motor or wheel if assembly does not operate or meet performance standards 1 hour soft lockout Clears after circula E 292 Indoor blower motor unable to start due to obstructed wheel seized Indoor blower motor unable to start seized bear tor successfully starts E 294 Combustion air inducer over current Check co
74. ure sensor failure Only shown if shorted or out of Compare outdoor sensor resistance to temperature resistance charts in unit installation instructions Replace sensor pack if necessary At beginning of any configuration furnace or air handler control will sense outdoor air and discharge air temperature ate feature will be set as installed and that could sensor s If detected reading in range appropri be seen in About screen In normal operation after control recognizes sensors alarm will be sent if valid temperature reading is lost To get rid of set ting and alarm redo configuration and make sure that temperature sensor is marked as not installed in Indoor Unit About screen When Indoor unit con trol is replaced thermostat will tell new control if temperature sensor is in system or not Clears 30 seconds after fault recovered E 200 Hard lockout Rollout circuit open or previously open Correct cause of rollout trip or replace flame rollout Switch Test furnace operation Cleared after fault recovered E201 Indoor blower communication failure Unable to communicate with blow Indoor blower communication failure including pow er motor er outage Lost communication with indoor blower motor Possible causes motor not powered loose wiring Problem may be on control or motor side Cleared after fault recovered Furnace Air Handler on configuration guide or in installation instructions Cle
75. when button released Solid E Solid D Solid F Solid P variable speed only No change idle Remain in idle mode Enter diagnostic recall mode Discharge Air Installed Enter flame signal mode Program unit capacity size Unit Code No change implies the display will continue to show whatever is currently being displayed for normal operation blinking decimal active error code heat state etc Diagnostic LED Figure 4 The seven segment diagnostic LED displays operating status target airflow error codes and other information The table beginning on 9 lists diagnostic LED codes Diagnostic Push Button Figure 4 The diagnostic push button is located adjacent to the seven segment diagnostic LED This button is used to en able the Error Code Recall E mode and the Flame Signal F mode Press the button and hold it to cycle through a menu of options Every five seconds a new menu item will be displayed When the button is released the displayed item will be selected Once all items in the menu have been displayed the menu resumes from the beginning until the button is released Error Code Recall Mode Select E from the menu to access the most recent 10 error codes Select the Error Code Recall menu to clear all error codes Button must be pressed a second time while is flashing to confirm command to delete codes Press the button until a soli
76. with perma gum Connect the zero end of the manometer to the dis FIGURE 16 charge supply side of the system On ducted sys tems connect the other end of manometer to the return duct as above Open all return air registers and check for clean filter 3 With only the blower motor running and the evaporator coil dry observe the manometer reading Adjust blow er motor speed to deliver the air desired according to the job requirements For heating speed external static pressure drop must not be more than 0 8 W C For cooling speed external static pressure drop must not be more than 1 0 W C 4 Seal the hole when the check is complete Page 31 VI MAINTENANCE AWARNING Disconnect power before servicing unit ACAUTION Label all wires prior to disconnection when servicing controls Wiring errors can cause improper and dan gerous operation Verify proper operation after ser At the beginning of each heating season a qualified techni cian should check the system as follows A Blower Check the blower wheel for debris and clean if necessary The blower motors are prelubricated for extended bearing life No further lubrication is needed AWARNING The inner blower access panel and vent pipe must be securely in place when the blower and burners are operating Gas fumes which could contain carbon monoxide can be drawn into living space resulting in personal injury or death B Filters A

Service Manual 11/2011

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