Trane Heat Pump Troubleshooting

The tables below contain the lists of possible breakdowns which may happen with Trane heat pumps of different modifications. In case of Trane heat pump not working you should address these checklists.

There are types of faults and problems with detailed descriptions, possible causes and solutions which may be recommended in the certain situations. If you feel the temperature in your house is getting higher, it may be because of heat pump fan not spinning, and therefore, heat pump not cooling. The information given below can be helpful for you then.

Trane 4WCC30 Series Heat Pump Troubleshooting

ProblemPossible causeRemedy
Insufficient heating or coolinga. dirty filtersa. clean or replace
b. air not circulating freelyb. check supply registers and return grills for blockage
c. blocked outdoor coilc. clear away leaves or other debris
Failure to operatea. power offa. make sure main switch is in ON position
b. open circuit breaker or burned-out fusesb. reset circuit breaker, or replace burned-out fuses
c. improperly adjusted thermostatc. check setting, adjust thermostat
Blue auxiliary heat light onWhen outdoor temperature falls, intermittent lighting is normal.Monitor light. If it stays on continuously when above 30°F, or if it comes on when 50°F outdoors, call for service.
No heating or cooling - Blower does not operateBlower door removed or ajarClose door securely to restore power to blower
Unusual noiseCall your local servicer

Trane CGA Series Heat Pump Troubleshooting

FLASH RATE INDICATIONS:SOLUTION
1 — Flash/SecondNormal Operation
2 — Flashes/Second!ERROR! B3 -> Formula Error: An unexpected error occurred
3 — Flashes/Second#NAME?
Fault C (High DT) i.e.: SOV stuck in heating, shorted ambient sensor, open coil sensor, closed TXV,OD motor failure, OD fan on in defrost, undercharged unit.
4 — Flashes/SecondFault A + Fault B + Fault C

Trane DCY048F4 Heat Pump Troubleshooting

CodeDescriptionInformation
bDInternal fault/power-up errorOn initial trial for ignition. Automatic reset is immediate once the gas valve relay check results are acceptable.
bDGas valve sensed as “ON” errorIf valve is open when it should be closed the heater will shut down and go into lockout. Blower will operate until error condition is corrected. Automatic restart 2 minutes after error is corrected.
bDGas valve sensed as “OFF” errorIf valve is closed but flame is sensed the blower will run for 5 s then start a new ignition sequence. If error occurs 10 times during a call for heat the control will go into lockout. Automatic reset is 60 minutes.
bDData retrieval errorIf control input data is corrupted the heater will shut down and go into lockout.
HFFlame present with gas valve “OFF” errorIf flame is sensed with the gas valve off the control will go into lockout. The blower will run until error condition is corrected. When corrected, control will run blower for 5 s then automatically restart after 2 minutes.
PFElectrical supply wiring errorThis code will display if 120V polarity is reversed, low voltage is detected, or if the ground path is not sufficient. Reset is immediate after error is corrected.
AOBlower vacuum switch open errorIf the blower prover switch does not close after the blower starts the control will stop the ignition trial go into lockout. The blower will continue to run. Automatic reset is immediate after the switch closes.
AOBlower vacuum switch open when expected closed errorIf the blower prover switch opens unexpectedly during operation the control will shut down and attempt to re-light. If the switch does not close after the blower starts the control will go into lockout with the blower running. Automatic reset is immediate after error is corrected.
AOBlower vacuum switch open during post-purge errorIf the blower prover switch opens during the post-purge cycle (heater is not fir- ing) the control will display the error code. The post-purge cycle will be completed once the blower prover switch closes.
ACBlower vacuum switch closed when expected open errorIf the blower prover switch is closed before blower start-up the control will not start the blower. Automatic reset is immediate when the switch opens.
IOIgniter open errorIf the control is not in lockout and senses that the igniter circuit is open when the blower is running the control will turn off the blower and go into lockout. Automatic restart 2 min after error is corrected.
SFThermistor errorAn excessive temperature difference between the two thermistors (5 °F or more) or an “out of bounds” condition on both sensors (less than 10°F or greater than 180°F) will result in the error code. Automatic restart is 2 minutes after the error is corrected.
HSWater Temperature Sensing ErrorA) Inlet water temperature sensor is reporting a temperature in excess of 104°F. Normal operation resumes 2 minutes after inlet water temperature sensor reports temperatures of 104°F or less. This error functions in both normal and remote thermostat modes.
B) Inlet water temperature sensor is reporting a temperature change at a rate faster than 6°F in 60 seconds or less while the heater is firing, indicating a potentially damaging low water flow condition. Normal operation resumes when temperatures stabilize. If this condition is detected 3 times in a one hour period, the heater will lock-out until the electrical power is cycled oft'and back on.
SbKeypad button stuck closed errorIf one of the keypad buttons is closed (or pressed) for more than 30 s the error code will be displayed but the control will continue to function. The error code will be cleared when the condition is corrected.
IFIgnition failure errorIf the control exceeds the maximum number of ignition retries or recycles the heater will shut down and go into lockout. Automatic reset is 60 minutes.
CECommunication errorIf communication between the ignition board and the display board is not established within 3 s of power-up an error will be displayed. After communication is established, if it is lost for 30 s, the error will be displayed. The error code will be cleared upon a valid data exchange between boards.
LOLimit string open errorIf the limit string opens the heater shuts down and goes into lockout. Automatic restart is 2 minutes after the error condition is corrected and the limit string closes.
EEEEPROM ERRORAn error was detected in the ignition control circuit board.

Trane GECA -006 Heat Pump Troubleshooting

FaultDiagnosis StepRemedy
Heater will not power up.1. Check for Low & High Voltage Output from Fuse BoardDisconnect plug from P5 connector from Fuse Board.
Measure for 24 VAC between pins of receptacle on Fuse Board. Reconnect plug. Disconnect plug from P6 of Fuse Board. Measure for 120VAC between pin 3 and 5 of receptacle on Fuse Board. Reconnect plug. If OK, proceed to section titled “Low voltage circuit fault”. Otherwise, proceed to step 2.
2. Ensure field power supply to heater is turned on.Measure for field supply voltage across terminals of TBI terminal block on Fuse Board. If OK, proceed to step 3
3. Check for faulty Fuse Board wiring.Insoect Fuse Board wiring. Ensure all plugs are securely fastened to Fuse Board. If OK, proceed to step 4.
4. Verify that FC1 and FC2 Fuses on Fuse Board are not open.Remove FC1 and FC2 fiises from fuseholder. Measure continuity across fuse. If fuses are open, proceed to section titled “Open FC1 and/or FC2 Fuses”. If fuses are OK, reinstall them and proceed to step 5.
5. Verify that 240vac Voltage Selector Plug is not installed with a 120vac field power supplyCheck that proper Volatage Selector Plug is installed in Fuse Board. If OK, proceed to step 6
6. Check for defective Transformer.Disconnect plug from P4 connector from Fuse Board. Mesure for 24VAC between pins 1 & 2 of plug of Transformer and 120VAC between pins 4 & 6. If 24VAC or 120VAC is not present, replace Transformer. Otherwise, proceed to step 7.
7. Fuse Board is defectiveReplace Fuse Board.
Low voltage circuit fault.1. Check for Low Voltage Output from Fuse BoardDiconnect plug from P5 connector from Fuse Board. Measure for 24VAC across pins. Reconnect plug. If OK, proceed to step 2. Otherwise, proceed to step 5.
2. Check for faulty Control Module wiring.Inspect Control Module wiring. Ensure all plugs are securly fastened to Control Module. If OK, proceed to step 3.
3. Verify low voltage input to Control Module.Verify 24VAC across R and C terminals on Control Module. If not OK, replace harness. If OK, procced to step 4.
4. Verify that FI Fuse on Control Board is not open.Remove FI fuse from fuseholder. Measure continuity across fuse. If OK, replace Control Module. If ftise is open, proceed to section titled “Open FC3 or FC1 Fuses”.
5. Verify that FC3 on Fuse Board is not openRemove FC3 fuse from fuseholder. Measure continuity across fuse. If ftise is open, proceed to section titled “Open FC3 or FC1 Fuses”. If OK, reinstall ftise and proceed to step 6.
6. Check for defective Transformer.Disconnect plug from P4 connector from Fuse Board. Mesure for 24VAC between pins 1 & 2 of plug from transformer.
If 24VAC is not present, replace Transformer. Otherwise, proceed to step 7.
7. Fuse Board is defectiveReplace Fuse Board
Open FC1 and/ or FC2 Fuses.1. Verify that 120VAC Voltage Selector Plug is not installed with a 240VAC field power supply.Check that proper Voltage Selector Plug is installed. If OK, proceed to step 2.
If 120VAC plug is installed and field supply voltage is 240VAC, FC1 and FC2 fuses will have to be opened. Install the correct Voltage Selector Plug and new FC 1 and FC2 ftises.
2. Check for faulty Transformer wiring.Inspect Transformer wiring. Ensure insulation on wiring is not worn. If OK, proceed to step 3.
3. Defective TransformerReplace Transformer.
Open FC3 and/ or FI Fuses1. Check for faulty Gas Valve wiring.Inspect Gas Valve wiring. Ensure insulation on wiring is not worn. If OK, proceed to step 2.
2. Verify that Gas Valve is not defective.Mesure for resistance across Gas Valve terminals and between each terminal and ground. If short exists, replace Gas Valve. If OK, proceed to step 3.
3. Check for faulty Control Module wiring.Inspect Control Module wiring. Ensure insulation on wiring is not worn. If OK proceed to step 4.
4. Control Module is defective.Replace Control Module.
Open FC4 Fuse.1. Check for faulty Igniter wiring.Inspect Igniter wiring. Ensure insulation on wiring is not worn. If OK, proceed to step 2.
2. Check for faulty Blower wiring.Inspect Blower wiring. Ensure insulation on wiring is not worn. If OK, proceed to step 3.
3. Check for defective Igniter.Disconnect Igniter plug from Control Module. Measure resistance across Igniter. Resistance should be 10.9-19.7 ohms at at 77°F. If out of this range, replace igniter. If OK, proceed to step 4
4. Check for defective Blower.Disconnect Blower plug from Control Module. Measure resistance across Blower windings. Winding resistance across lead should be in the following range: Red-to-White: 4 to 5 ohms. If measured values vary substantially from these values, blower is defective. Replace. Otherwise proceed to step 5.
5. Control Module is defective.Replace Control Module.

Trane MWX530 G1 Heat Pump Troubleshooting

Fault LEDAlert CodeDescriptionControl Display
1 Flash90Excessive Communication ErrorsN/A
91Loss of Heat/Cool Demand Message (COMM)ERR 91
Loss Of Bit Master (Clock Signal)
2 FlashDefrost Fault A
3 Flash68Defrost Fault B and/or CN/A
4 FlashDefrost Fault A and [B and/or C]
5 Flash67Ambient Temperature Sensor Fault (Out of Range - Open or Shorted)ERR 67
6 FlashCoil Temperature Sensor Fault (Out of Range - Open or Shorted)
Low Pressure Cut Out Fault (Open outside of defrost Cyde-Hard lock out. cycle power to reset)ERR 79
7 Flash79Low Pressure Cut Out Fault Heat/Cool Lock out
Low Pressure Cut Out Fault (Open outside of defrost Cyde-Short lock out)Wait n
10 Flash102Y2 without Y1 - Miswire (24 volt mode only)N/A
11 Flash67Liquid Temperature Sensor Fault (Out of Range - Open or Shorted)N/A
12 Flash113Liquid Pressure Sensor Fault (Out of Range - Open or Shorted)ERR 113
13 Flash67External Outdoor Temperature Sensor Fault (Out of Range - Shorted)N/A
PM Missing with local copy (Operational)ERR 114
Bad Data in PM with local copy (Operational)N/A
14 Flash114Bad Data in PM no local copy (Not Operational)ERR 114
PM Missing with no local copy (Not Operational)
15 Flash50Duplicate OD Temperature SensorN/A
16 Flash123Demand Configuration FaultN/A
17 Flash80High Presure Monitor Fault (Hard lock out. cycle power to reset)ERR 80
High Presure Monitor Fault (Short lock out)Wait n
18 Flash1824V Sensing Error (24V Missing at Y1)ERR 18

Trane TWA Series Heat Pump Troubleshooting

LED ColorCharge Assist™ (CA) LEDsFlashingDescription
GreenCHARGEDOffCharged or not in CA Mode
OnCharge is Correct
Y1On1st stage compressor requests
Y2On2nd stage compressor request
Fast FlashInitialization at Power Up - 60 seconds
Med FlashOil Return Mode (Forced Defrost)
STATUSSlow FlashStandard operation
OffCharge Assist™ mode or no power to control
LltePortOccasional FlashFor transmitting LitePoct™ data
AmberCOMFlashingFlash device count when in communication (number of COMM products connected in system); Rapid flashes followed by a pause indicates disrupted communications
OffNo power
OnSolid at power-up
CHARGINGOffNot in CA Mode
ADDOnSystem requires refrigerant charge (Control has 24 volt AC output to Charge Solenoid)
RedODTFlashingAmbient Temperature is out of range - Ambient Temperature must be above 55°F and below 120°F to enter CA Mode Note: ODT LED with flash 1 sec ON/OFF for 30 seconds and the CHARGING LED flash 5 times per second for 2 seconds, then exit CA.
RECOVEROnNeed to recover refrigerant - Unit locked out for 1 hour or press mode button to exit Charge Assist™
LOWOnLiquid pressure below 90 psig - Liquid pressure must be above 90 psig to enter CA Mode
Note: LOW pressure LED will be on for 30 seconds and the CHARGING LED will flash 5 times per second for 2 seconds, then exit CA.