COMFORT-AIRE GUH97M Service Manual Download

Page: 1 / 70

508146-01

Issue 2051

Page 1 of 7

SERVICE MANUAL

GUH97M

Gas Furnace

(P) 508146-01

*P508146-01*

Table of Contents

Technical Specifications -

GUH97M..

...........................2

Parts Arrangement

.......................................................7

Unit Components

.........................................................8

Configuring Unit Size Codes

.....................................16

Placement and Installation

........................................3

Joint Cementing Procedure

.......................................3

Venting Practices

.......................................................3

Vent Piping Guidelines

..............................................3

Condensate Piping

....................................................4

Start-Up

.....................................................................5

Heating System Service Checks

...............................5

Typical Operating Characteristics

..............................5

Maintenance

..............................................................5

Wiring and Sequence of Operation

...........................

This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in manuals, be alert to

the potential for personal injury or death.

Electric shock hazard.
Can cause injury or death. Before attempting

to perform any service or maintenance,

turn the electrical power to unit OFF at

disconnect switch(es). Unit may have

multiple power supplies.

WARNING

As with any mechanical equipment, contact with sharp

sheet metal edges can result in personal injury. Take

care while handling this equipment and wear gloves

and protective clothing.

CAUTION

Improper installation, adjustment, alteration, service

or maintenance can cause property damage, personal

injury or loss of life. Installation and service must be

performed by a licensed professional HVAC installer (or

equivalent), service agency or the gas supplier.

WARNING

GUH97M series units are high-efficiency upflow,

horizontal right and left) gas furnaces equipped with

variable capacity gas valve, variable speed combustion

air inducer and variable speed indoor blower motor. All

models are designed only for direct vent (dual pipe)

venting system. GUH97M units are available in heating

capacities from 66,000 to 132,000 Btuh (19.3 to 38.6 kW)

and cooling applications from 2 to 5 tons (7.0 kW to 17.5

kW). Refer to Technical Specifications for proper sizing.

Units are factory-equipped for use with natural gas. Kits

are available for conversion to LPG operation. GUH97M

models include a variable capacity integrated control that

can be used with Comfort-Aire/Century Standard

thermostat. All GUH97M units meet the California

Nitrogen Oxides (NOx) Standards and California

Seasonal Efficiency requirements.

All specifications in this manual are subject to change.

Procedures outlined in this manual are presented as

recommendations 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 constitute code.

Field Wiring Applications with Conventional

Thermostat......................................

...........................

Sequence of Operation and Troubleshooting Flow

Char

...............................................

...........................

Summary of Contents for GUH97M

Page 1: ...e performed by a licensed professional HVAC installer or equivalent service agency or the gas supplier WARNING GUH97M series units are high efficiency upflow horizontal right and left gas furnaces equipped with variable capacity gas valve variable speed combustion air inducer and variable speed indoor blower motor All models are designed only for direct vent dual pipe venting system GUH97M units a...

Page 2: ...tput Btuh AFUE ICS Nominal Cooling Capacity Gas Inlet in Volts Hertz Phase Max Time Delay Breaker or Fuse Nominal F L A Trans V A Approx Shipping Weight lbs UPFLOW HORIZONTAL GUH97M070B3M 66 000 64 000 97 0 3 Tons 1 2 120 60 1 15 7 7 40 138 GUH97M090C3M 88 000 85 000 97 0 3 Tons 1 2 120 60 1 15 7 7 40 155 GUH97M090C4M 88 000 85 000 97 0 4 Tons 1 2 120 60 1 15 10 1 40 165 GUH97M090C5M 88 000 85 000...

Page 3: ...7 1444 1645 Default 716 1075 1434 10 938 1148 1324 1469 35 65 Min Input 1st Stage 10 843 1007 1159 1315 7 5 652 997 1342 Default 780 915 1047 1190 15 589 919 1249 10 693 838 959 1070 GUH97M090C5M 1 HP 11 x 11 50 80 Max Input 15 665 1159 1653 2nd Stage 10 1385 1593 1818 2019 7 5 618 1085 1553 Default 1226 1463 1647 1884 Default 571 1012 1453 10 1063 1320 1504 1675 35 65 Min Input 1st Stage 10 933 1...

Page 4: ... 1728 7 5 759 1127 1495 Default 1043 1235 1398 1566 Default 706 1051 1395 10 913 1124 1279 1402 35 65 Min Input 1st Stage 10 823 1009 1135 1292 7 5 608 814 1020 Default 758 882 1026 1151 15 571 747 923 10 684 816 928 1068 GUH97M090C5M 1 HP 11 x 11 50 80 Max Input 15 684 1136 1588 2nd Stage 10 1335 1559 1719 1986 7 5 623 1059 1496 Default 1173 1433 1568 1811 Default 562 983 1403 10 1049 1283 1451 1...

Page 5: ...7 1049 1206 1354 7 5 480 751 1021 Default 791 946 1093 1255 Default 441 696 951 10 722 845 987 1131 35 65 Min Input 1st Stage 10 596 717 816 950 7 5 408 643 877 Default 521 657 755 840 15 375 589 803 10 494 597 672 747 GUH97M090C3M 1 2 HP 10 x 9 60 90 Max Input 15 721 988 1254 2nd Stage 10 852 999 1166 1305 7 5 679 923 1167 Default 776 907 1050 1206 Default 637 858 1079 10 712 802 947 1074 35 65 M...

Page 6: ...r Base 68W62 17 5 B Width 68W63 21 0 C Width 68W64 24 5 D Width Night Service Kits 89W52 Modulating Horizontal Suspension Kit 51W10 80 90 Kit Flush Mount Termination 90 Furnaces only US Only 51W11 2 3 Vent Version Concentric Vent Kit 90 Furnaces only US Only 71M80 1 1 2 Vent Version 69M29 2 Vent Version 60L46 3 Vent Version For vent length and clearances to combustibles please reference installati...

Page 7: ...508146 01 Issue 2051 Page 7 of 70 Figure 1 Parts Arrangement ...

Page 8: ...sformer T1 The breaker is rated 3A at 32V If the current exceeds this limit the breaker will trip and all unit operation will shutdown The breaker can be manually reset by pressing the button on the face See Figure 3 PRESS TO RESET Figure 3 Circuit Breaker CB8 Shock hazard Disconnect power before servicing Integrated control is not field repairable If control is inoperable simply replace entire co...

Page 9: ... are only operational with a two stage thermostat The thermostat selection is made using dip switches one and or two Figure 4 and must be positioned for the particular application Variable Capacity Using a two stage thermostat the system will operate in a variable capacity sequence mode In this mode the control will vary the firing rate anywhere between 35 and 100 of full capacity The indoor blowe...

Page 10: ...HUMIDIFICATION 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 CHASIS GROUND GRD Y1 THERMOSTAT 1ST STAGE COOL SIGNAL Y2 THERMOSTAT 2ND STAGE COOL SIGNAL O THERMOSTAT SIGNAL TO HEAT PUMP REVERSING VALVE H 24V HUMIDIFIER OUTPUT DO NOT CONNECT TO COMFORT...

Page 11: ...508146 01 Issue 2051 Page 11 of 70 Figure 5 Integrated Control Configuration Guide ...

Page 12: ...atisfy individual 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 settings provide higher supply air temperatures Table 4 provides the blower off timings that will result from different switch settings Blower Off Delay Seconds...

Page 13: ...and is met motor ramps down to stop OFF OFF 82 CFM 100 CFM COMPRESSOR DEMAND 7 1 2 MIN Ramping Option C Motor runs at 100 until demand is satisfied Once demand is met motor runs at 100 for 45 seconds then ramps down to stop OFF OFF 100 CFM 100 CFM 45 SEC COMPRESSOR DEMAND Ramping Option D Motor runs at 100 until demand is satisfied Once demand is met motor ramps down to stop OFF OFF 100 CFM COMPRE...

Page 14: ...gure 4 On board link W915 is a clippable connection between terminals Y1 and Y2 on the integrated control W915 must be cut if two stage cooling will be used If the link is not cut the outdoor unit will operate in second stage cooling only Diagnostic LED Figure 4 The seven segment diagnostic LED displays operating status target airflow error codes and other information Table 13 lists diagnostic LED...

Page 15: ...playing the soft disable code 1 Confirm proper wiring between all devices thermostat damper control module indoor and outdoor 2 Cycle power to the control that is displaying the soft disable code 3 Put the room thermostat through set up 4 Go to setup system devices thermostat edit then push reset 5 Go to setup system devices thermostat edit then push resetAll These options are displayed on the men...

Page 16: ...ze code is correct and stored in 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 the board does not recognize the unit size code The programming function must be repeated FINISHED If alarm is present furnace control will display error code If alarm is ...

Page 17: ...s System resumes normal operation 5 seconds after fault recovered E115 Low 24V Control will restart if the error recovers 24 Volt Power high Range is 18 to 30 Volts Check and correct voltage Check for additional power robbing equipment connected to system May require installation of larger VA transformer to be installed in furnace air handler Clears after fault recovered E120 Unresponsive device C...

Page 18: ...stallation instruction Critical Alert Cleared after valid unit code is read following a reset remove thermostat from system while applying power and reprogramming E204 Gas valve mis wired Check gas valve operation and wiring Clears when repaired E205 Gas valve control relay contact shorted Check wiring on control and gas valve If wiring is correct replace control E207 Hot surface igniter sensed op...

Page 19: ...ral to ground to ensure good unit ground Alert clears after current heat call has been completed E274 Soft lockout Exceeded maximum number of recycles Last recycle failed due to the limit circuit opening or limit remained open longer than 3 minutes Shut down system 1 hour soft lockout Check firing rate and air flow Check for blockage Clears when heat call finishes successfully E275 Soft lockout Fl...

Page 20: ...en R O on integrated control with non communicating outdoor unit dual fuel model required for heat pump application Configuration link R to O needs to be restored Replace link or hardware Applicable in non communicating mode Critical Alert E401 LSOM Compressor long run cycle or low system pressure Compressor ran more that 18 hours to satisfy a single thermostat demand Critical Alert Clears the err...

Page 21: ...ODE operates independent of a Y1 thermostat demand Normal Operation 1 On On On Acceptable 24 VAC High 100 Dehumidification mode begins when humidity is greater than set point Maximum overcool from cooling setpoint is 2 F Dehumidification Call 2 On On On Demand 0 VAC High 70 Dehumidification Call ONLY 1 On On On Demand 0 VAC High 70 Thermostat will keep outdoor unit energized after cooling temperat...

Page 22: ...mperature setpoint has been reached in order to maintain room humidity setpoint Maximum overcool from cooling setpoint is 2 F ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING BASIC MODE only active on a Y1 thermostat demand Normal Operation 1 On On On On Acceptable 24 VAC High 100 Thermostat energizes 2nd Stage and de energizes D on a call for de humidification Dehumidification Call 2 On O...

Page 23: ...R Figure 8 Blower Motor Components 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 sequence the rotor shaft turns the blower All GUH97M blower motors use single phase power An external run capacitor is not used The motor uses permanently lubricated ball type bearing...

Page 24: ...wer from unit and wait at least five minutes to allow capacitors to discharge before attempting to service motor Failure to wait may cause personal injury or death DANGER Power Choke L13 A choke coil is used on GUH97M 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 Remove Blower from Unit 1 Remove unit access p...

Page 25: ...in P48 5 Pin J48 5 Pin Line Voltage Connector J49 4 Pin Control Connector J48 5 Pin J49 4 Pin MOTOR with INTEGRATED CONTROLLER SHAFT P49 4 Pin P48 5 Pin P48 5 Pin P49 4 Pin J48 Connector installed on motor P49 4 Pin 120v 0 240v 5 4 3 2 1 J48 Connector 24v Transformer J49 Connector Figure 10 Blower B3 Harness Connectors ...

Page 26: ...ead resistance should be the same If the measured resistance is greater than 20 ohms replace the motor and control module Figure 13 Test B Heating Components Ignitor The ignitor is made of durable silicon nitride Ignitor longevity is enhanced by controlling voltage to the ignitor The integrated control provides 120 volts to the ignitor for a consistent ignition Due to this feature of the control v...

Page 27: ...t Always operate the unit with the burner box front panel in place Each burner uses an orifice that is precisely matched to the burner 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 Maintenance Heat Exchanger Figure 15 GUH97M units...

Page 28: ... Danger of explosion There are circumstances in which odorant used with LP propane gas can lose its scent In case of a leak LP propane gas will settle close to the floor and may be difficult to smell An LP propane leak detector should be installed in all LP applications DANGER The burner box is sealed and operates under a negative pressure A pressure hose is connected from the burner box to the ga...

Page 29: ...e switch open RPM margin value 3 If low pressure switch is open set flag for calibration on next call for heat Turn inducer off until next call for heat 4 If low pressure switch is closed move inducer speed to RPM1 Allow 5 seconds for stabilization Finally the switch interrupts the combustion process if the condensate drainage system becomes blocked to the point the condensate level builds up in t...

Page 30: ...e switch measures the pressure differential across the CAI orifice difference in the channel and cold end header box If replacement is necessary the gaskets used to seal the box to the vestibule panel and the CAI to the box must also be replaced Unit Set Point High Fire Set Point Low Fire All 1 00 0 05 0 25 0 05 Units over 7500 ft will require a conversion kit See Table 30 Table 18 Pressure Switch...

Page 31: ... is recommended during cooler weather Metal or plastic strapping may be used for vent pipe hangers Uniformly apply a liberal coat of PVC primer for PVC or use a clean dry cloth for ABS to clean inside socket surface of fitting and male end of pipe to depth of fitting socket Canadian Applications Only Pipe fittings primer and solvent cement used to vent exhaust this appliance must be certified to U...

Page 32: ...d of pipe into socket until it bottoms out Turn PVC pipe 1 4 turn during assembly but not after pipe is fully inserted to distribute cement evenly DO NOT turn ABS or cellular core pipe NOTE Assembly should be completed within 20 seconds after last application of cement Hammer blows should not be used when inserting pipe 8 After assembly wipe excess cement from pipe at end of fitting socket A prope...

Page 33: ...n home make provisions for draining condensate collection trap and lines Exhaust Piping Figure 22 and Figure 23 Route piping to outside of structure Continue with installation following instructions given in piping termination section Intake Piping Figure 22 and Figure 23 The GUH97M furnace may be installed only in direct vent applications The GUH97M is designed for combustion air intake through a...

Page 34: ...Figure 23 Typical Exhaust and Intake Pipe Connections and Condensate Trap Installation in Horizontal Air Applications Right Hand Discharge Shown SIDE VIEW 45 MAX 45 MAX 2 2 2 or 2 2 12 max EXHAUST 2 2 2 2 2 INTAKE 1 1 2 2 2 EXHAUST NOTE 1 1 2 Vent Pipe Diameter Allowed Only on 070 Units DO NOT transition from larger to smaller pipe in horizontal runs of exhaust pipe EXHAUST EXHAUST DO NOT transiti...

Page 35: ...on Refer to Table 24 In some applications which permit the use of several different sizes of vent pipe a combination vent pipe may be used Contact Comfort Aire Century for assistance in sizing vent pipe in these applications NOTE The exhaust collar on all models is sized to accommodate 2 Schedule 40 vent pipe In horizontal applications any transition to exhaust pipe larger than 2 must be made in v...

Page 36: ...nt pipe diameter Figure 25 070 090 110 or 135 btuh Standard or Concentric See Table 20 Intake or Exhaust 1 1 2 2 2 1 2 or 3 Furnace capacity 1 Which termination 2 Which needs most elbows 3 How many 4 Desired pipe size 5 What is the altitude 6 Use Table 22 to find max pipe length 7 ...

Page 37: ... 29 100 53 n a 122 103 78 74 9 46 24 95 48 117 98 73 69 10 41 19 90 43 112 93 68 64 Standard Termination at Elevation 4 501 10 000 ft Number of 90 Elbows Used 1 1 2 Pipe 2 Pipe 2 1 2 Pipe 3 Pipe Model Model Model Model 70 90 110 135 70 90 110 135 70 90 110 135 70 90 110 135 1 12 n a n a n a 61 39 n a n a 110 63 n a n a 132 113 88 84 2 7 56 34 105 58 127 108 83 79 3 n a 51 29 100 53 122 103 78 74 4...

Page 38: ...70 8 43 27 90 49 106 99 74 65 9 38 22 85 44 101 94 69 60 10 33 17 80 39 96 89 64 55 Concentric Termination Elevation 4 501 10 000 ft Number of 90 Elbows Used 1 1 2 Pipe 2 Pipe 2 1 2 Pipe 3 Pipe Model Model Model Model 70 90 110 135 70 90 110 135 70 90 110 135 70 90 110 135 1 10 n a n a n a 53 37 n a n a 100 59 n a n a 116 109 84 75 2 n a 48 32 95 54 111 104 79 70 3 43 27 90 49 106 99 74 65 4 38 22...

Page 39: ...mmended that the exhaust outlet not be located within 6 feet 1 8m of an outdoor AC unit because the condensate can damage the painted coating NOTE See Table 23 for maximum allowed exhaust pipe length without insulation in unconditioned space during winter design temperatures below 32 F 0 C If required exhaust pipe should be insulated with 1 2 13mm Armaflex or equivalent In extreme cold climate are...

Page 40: ...0 to 20 18 to 29 1 1 2 in N A N A N A N A N A N A N A N A 2 in N A N A N A N A N A N A N A N A 2 1 2 in N A N A N A N A N A N A N A N A 3 in N A N A N A N A N A N A N A N A 1 Refer to 99 Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook 2 Poly Propylene vent pipe PP by Duravent and Centrotherm 3 Vent length in table is equivalent length Each elbow...

Page 41: ...152mm for appliances 10 000 pliances 10 000 Btuh 3kw and 50 000 pliances 50 000 Btuh 15kw 6 inches 152mm for appliances 10 000 Btuh 3kw 12 inches 305mm for appliances 10 000 Btuh 3kw and 100 000 Btuh 30kw 36 inches 9m for appliances 100 000 Btuh 30kw 3 feet 9m above if within 10 feet 3m horizontally 6 feet 1 8m 7 feet 2 1m 12 inches 305mm For clearances not specified in ANSI Z223 1 NFPA 54 or CSA ...

Page 42: ...urnace Inlet Air Minimum 12 in 305MM above grade or snow accumulation Figure 29 Exiting Exhaust and Intake Vent no common pressure zone 2 Intake and exhaust pipes should be placed as close together as possible at termination end refer to illustrations Maximum separation is 3 76MM on roof terminations and 6 152MM on side wall terminations NOTE When venting in different pressure zones the maximum se...

Page 43: ...ROVIDED REDUCER MAY BE REQUIRED TO ADAPT LARGER VENT PIPE SIZE TO TERMINATION 12 305mm INTAKE AIR EXHAUST VENT Figure 32 Direct Vent Concentric Rooftop Termination 71M80 69M29 or 60L46 US 41W92 or 41W93 Canada Figure 33 Direct Vent Application Using Existing Chimney STRAIGHT CUT OR ANGLE CUT IN DIRECTION OF ROOF SLOPE EXHAUST VENT 1 2 13mm WEATHERPROOF INSULATION SHOULDER OF FITTINGS PROVIDE SUPPO...

Page 44: ...ance above grade or average snow accumulation B Horizontal separation between intake and exhaust C Minimum from end of exhaust to inlet of intake D Exhaust pipe length E Wall support distance from top of each pipe intake exhaust 12 305 mm Min 12 305 mm Min 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 16 405 mm Max 6 152 mm Max 6 152 mm Min 24 610 mm Max 9 227 mm Min 12 305 mm Min 20 508 m...

Page 45: ...ces with a 3 4 drain connection use a large flat head screw driver or a 1 2 drive socket extension and remove plug Install provided 3 4 NPT street elbow fitting into cold end header box Use Teflon tape or appropriate pipe dope 3 Install the cap over the clean out opening at the base of the trap Secure with clamp See Figure 45 and Figure 46 4 Install drain trap using appropriate PVC fittings glue a...

Page 46: ...in line If this is not possible a heat cable kit may be used on the condensate trap and line Heating cable kit is available in various lengths 6 ft 1 8m kit no 26K68 and 24 ft 7 3m kit no 26K69 Condensate DrainConnection Field Provided Vent 1 min 2 max above condensate connection Evaporator drain line required Trap at coil is optional Figure 40 Furnace with Evaporator Coil Using a Separate Drain U...

Page 47: ...ator drain line required Trap at coil is optional Field Provided Vent Figure 43 Furnace with Evaporator Coil Using a Common Drain Unit shown in horizontal left hand discharge position Condensate Drain Connection 4 min to 5 Max above condensate drain connection 5 max PVC Pipe Only Evaporator Coil Drain Pan Piping from furnace and evaporator coil must slope down a minimum 1 4 per ft toward trap Trap...

Page 48: ... 2 inch PVC Pipe Not Furnished Drain Assembly for 3 4 inch Drain Pipe Condensate Drain Connection In Unit Condensate Drain Connection In Unit Vent To Drain Condensate Drain Connection In Unit Optional Condensate Drain Connection OptionalDrainPipingFromTrap DrainTrapAssembly Furnished DrainTrap Assembly with 1 2 inch Piping DrainTrap Assembly with 3 4 inch Piping 1 2 inch 3 4 inch 1 25 mm Min 2 50 ...

Page 49: ...ow 1 2 inch PVC To Drain 90 Elbow 1 2 inch PVC Not Furnished 1 2 inch PVC Pipe Not Furnished Drain Assembly for 3 4 inch Drain Pipe 90 Street Elbow 1 2 inch PVC Not Furnished Condensate Drain Connection In Unit Adapter 1 2 inch slip X 1 2 inch mpt Not Furnished Condensate Drain Connection In Unit Vent To Drain Condensate Drain Connection In Unit Drain Trap Assembly with 3 4 inch Piping Vent To Dra...

Page 50: ...hand replace the valve Do not try to repair it Force or attempted repair may result in a fire or explosion Placing the Furnace into Operation GUH97M units are equipped with an ignition system Do NOT attempt to manually light burners on this furnace Each time the thermostat calls for heat the burners will automatically light The ignitor does not get hot when there is no call for heat on units with ...

Page 51: ... the unit ignition system in lockout If the unit locks out again inspect the unit for blockages 10 Is blower harness connected to integrated control Furnace will not operate unless harness is connected Safety or Emergency Shutdown Turn off unit power Close manual and main gas valves Extended Period Shutdown Turn off thermostat or set to UNOCCUPIED mode Close all gas valves both internal and extern...

Page 52: ...e and should not lift from burner Natural gas should burn blue 5 After allowing unit to run for 5 minutes record manifold pressure and compare to value given in Table 29 6 Repeat steps 3 4 and 5 on high fire 7 Shut unit off and remove manometer as soon as an accurate reading has been obtained Take care to remove barbed fitting and replace threaded plug 8 Start unit and perform leak check Seal leak...

Page 53: ...70 Field Installed Gas Valve Figure 49 Manifold Pressure Measurement Negative Port Positive Port Gas Valve Measuring Device Field Installed Black Tubing Red and Black Tubing or Red Tubing Figure 50 Operating Signal Delta P Measurement ...

Page 54: ...titudes The combustion air pressure switch is factory set and requires no adjustment Firing Rate Manifold Pressure Nat Gas Manifold Pressure LP Propane Operating Pressure Signal Delta P Min Normal Max Min Normal Max Min Normal Max 40 0 5 0 6 0 7 1 3 1 6 1 9 0 25 0 30 0 35 70 1 7 1 9 2 1 5 1 5 5 5 9 0 60 0 65 0 70 100 3 2 3 5 3 8 9 5 10 0 10 5 1 10 1 15 1 20 NOTE A natural to LP propane gas changeo...

Page 55: ...operate on second stage heat If using a single stage thermostat furnace must fire at least 10 minutes before switching to second stage heat 3 After plenum thermometers have reached their highest 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 If temperature is too high first c...

Page 56: ... foam filters If the pressure drop is too great system capacity and performance may be reduced The pressure drop may also cause the limit to trip more frequently during the winter and the indoor coil to freeze in the summer resulting in an increase in the number of service calls Before using any filter with this system check the specifications provided by the filter manufacturer against the data g...

Page 57: ... disconnect all combustion air pressure tubing from cold end header collector box 12 Mark and remove wires from pressure switches Remove pressure switches Keep tubing attached to pressure switches 13 Disconnect the 4 pin plug from the combustion air inducer Remove two screws which secure combustion air inducer to collector box Remove combustion air inducer assembly Remove ground wire from vest pan...

Page 58: ...lace heating compartment access panel Cleaning the Burner Assembly 1 Turn off electrical and gas power supplies to furnace Remove upper and lower furnace access panels 2 Disconnect the 2 pin plug from the gas valve 3 Remove the burner box cover 4 Disconnect the gas supply line from the gas valve Remove gas valve manifold assembly 5 Mark and disconnect sensor wire from the sensor Disconnect 2 pin p...

Page 59: ...508146 01 Issue 2051 Page 59 of 70 Wiring and Sequence of Operation Figure 53 ...

Page 60: ... is still present the furnace will continue to operate at the present firing rate until the heat cycle ends 7 When the demand for first and second stage heat is satisfied the gas valve is de energized and the field selected indoor blower off delay begins The combustion air inducer begins a 20 second post purge period 8 When the combustion air post purge period is complete the inducer is de energiz...

Page 61: ...45 second ON delay When the delay ends the indoor blower motor is energized at a speed that matches the firing rate After the 10 second ignition stabilization delay expires the inducer speed is adjusted to the appropriate target rate The inducer will remain at the 70 percent speed as long as the thermostat has a first stage heating demand 5 If second stage heat is required the thermostat second st...

Page 62: ...tact Intact Intact T STAT CONTROL TERM STRIP OUTDOOR UNIT 1 Heat 2 Cool NOTE Use DIP switch 3 to set sceond stage heat ON delay OFF 7 minutes ON 12 minutes ON Cut Intact Intact T STAT CONTROL TERM STRIP OUTDOOR UNIT 1 Heat 2 Cool with t stat with dehumidification mode NOTE Use DIP switch 3 to set sceond stage heat ON delay OFF 7 minutes ON 12 minutes ON Cut Cut Intact T STAT CONTROL TERM STRIP OUT...

Page 63: ... 2 Cool OFF Cut Intact Intact T STAT CONTROL TERM STRIP OUTDOOR UNIT 2 Heat 2 Cool with t stat with dehumidification mode OFF Cut Cut Intact T STAT CONTROL TERM STRIP OUTDOOR UNIT 2 Heat 1 Cool OFF Intact Intact Intact T STAT CONTROL TERM STRIP OUTDOOR UNIT R required on some units Connect W1 to W1 ONLY if using defrost tempering kit 67M41 Table 32 Field Wiring for Non Communicating Thermostat App...

Page 64: ...2 stage gas heat control OFF Intact Intact Cut T STAT CONTROL TERM STRIP HEAT PUMP 67M41 Y H L Y2 D B L Y2 T T outdoor sensor Dual Fuel Two Stage Heat Pump Capable of 2 stage gas heat control OFF Cut Intact Cut CONTROL TERM STRIP HEAT PUMP out blue 67M41 H L Y2 D B L Y2 T T outdoor sensor T STAT R required on some units Connect W1 to W1 ONLY if using defrost tempering kit 67M41 Table 32 Field Wiri...

Page 65: ...Purge 20Seconds Soft Lockout Error Code Flashes YES NO NO YES Call For Heat Ends NO YES YES NO C A L L F O R 1 S T S T A G E H E A T 3A 2 1 1 OR Call For Heat NO 4 Calibrations Attempted Calibration Successful Wait 5 minutes NO NO Soft Lockout Error Code Flashes YES YES YES 2 1 1 2 Set Target Firing Rate Based on Thermostat Signals Present SOF T LOCKOU T IS RESE T AUTOMATICALLY AFTER ONE HOUR WITH...

Page 66: ...ithin 10 Seconds NO Error Code Flashes NO YES Wait 5 Minutes 3A 2 1 2 1 System will always light at 70 even if 2nd stage call for heat is in place If the high pressure switch does not close within 5 attempts the system will operate at low fire for the remainder of the call for heat at request Combustion Air Inducer ON 100 Rate Speed Increase Combustion Air Inducer Speed if Not at 100 Rate Speed Ad...

Page 67: ... YES OR Combustion Air Inducer switched to 70 rate speed Adjust Indoor Blower to appropiate speed Combustion Air Inducer OFF after 20 Second Post Purge Indoor Blower OFF after OFF Delay RUN MODE 2 STAGE THEREMOSTAT 1ST OR 2ND STAGE CALL FOR HEAT ALL INPUTS MONITORED LIMIT PRESSURE CALL FOR HEAT COOL FLAME LEVEL RUN MODE SINGLE STAGE THERMOSTAT ALL INPUTS MONITORED LIMIT PRESSURE CALL FOR HEAT COOL...

Page 68: ...oft Lockout Error Code Flashes YES NO NO YES Call For Heat Ends NO YES YES NO C A L L F O R H E A T 3B 1 4 Move to Mid Firing Rate and High Firing Rate after 2nd and 3rd Stage Delays based on DI P Switch selections Pressure Switch Calibration Call For Heat NO 4 Calibrations Attempted Calibration Successful Wait 5 minutes NO NO Soft Lockout Error Code Flashes YES YES YES SOFT LOCKOUT IS RESE T AUTO...

Page 69: ...gh Cooling mode High Cooling mode Per Ramping Profile NO NO YES NO 5 1 2 1 2 2 2 1 Indoor Blower On After 2 second delay Energize Indoor Blower Per Ramping Profile Energize Indoor Blower Maintain Indoor Blower Maintain Indoor Blower at De EnergizeIndoor Blower 2nd stage cooling operation requires a 2 stage thermostat a 2 stage cooling system and jumpers W915 must be be cut The control will not res...

Page 70: ...1 4 5 1 1 Call for Continuous Blower Indoor Blower On Maintain Indoor Blower at set speed Maintain Indoor Blower at set speed OR Maintain Indoor Blower at set speed Indoor Blower Per Go to Call for Heat Single Stage Thermostat Indoor blower low cooling mode and high cooling mode have specific ON OFF and speed ramping profiles The specific profile is selected using the dip switches on the control F...

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