The tables below contain the lists of possible breakdowns which may happen with Carrier heat pumps of different modifications. In case of Carrier heat pump not working you should address these checklists. Here you can find the failures of modifications like AQUAZONE, COMFORT, Infinity, Deluxe, and others.
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.
CHECK | POSSIBLE CAUSE | SOLUTION |
---|---|---|
Is fault LED Blinking 1 time? | High Pressure fault - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. |
High Pressure fault - high water temperature | Check water temperature - is it in range? | |
High Pressure fault - fouled or scaled water coil | Check for proper flow rate and water temperature, but low water side temp rise in cooling. | |
Check fan motor for proper operation. | ||
Is fault LED Blinking 2 times? | High Pressure fault - no or low airflow | Check air filter. |
Inspect air coil for dirt/debris. | ||
Check ductwork - are dampers closed or blocked? | ||
Low Pressure fault - no or low airflow | Check fan motor for proper operation. | |
Check air filter | ||
Inspect air coil for dirt/debris | ||
Check ductwork - are dampers closed or blocked? | ||
Low Pressure fault - low refrigerant | Check refrigerant pressure with gage set | |
Is fault LED Blinking 3 times? | Low Pressure fault - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. |
Low Pressure fault - low refrigerant | Check for proper flow rate and water temperature, but low water side temp drop in heating. | |
Freeze fault, water coil - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. | |
Freeze fault - low water temperature | Check water temperature - is it below 40 F entering? If heat pump is connected to a closed loop with anti- freeze check that the "FREEZE 1 * resistor on the Complete C board has been cut to set the unit to anti- freeze mode. | |
Freeze fault - low refrigerant | Check refrigerant pressure with gage set | |
Blinking 4 times? | Condensate fault - poor drain- age | Check condensate pan for high water level. Check drain line for blockages, double trapping or inadequate trapping. |
Condensate fault - blocked return air | Check condensate pan for high water level. Check air filter and return air ductwork tor blockage. Check that there is adequate space between the return air opening and walls or other obstructions on free return applications. | |
Is fault LED Blinking 5 times? | Brown out fault - low supply voltage | Check primary voltage - ensure it is within the limits listed on the unit data plate. |
Brown out fault - overloaded control circuit | Check control voltage - if it is below 18 V check accessories connected to the unit and insure that they do not exceed the VA draw | |
Brown out fault - bad thermostat connection | Check that thermostat wiring is proper gage and length, that it is not damaged and that all connections at the thermostat and heat pump are secure. | |
Is fault LED Blinking 6 times? | Freeze fault, air coil - no or low airflow | Check fan motor for proper operation. |
Check air filter | ||
Inspect air coil for dirt/debris | ||
Check ductwork - are dampers closed or blocked? | ||
Freeze fault, air coil - blocked return air | Check that there is adequate space between the return air opening and walls or other obstructions on free return applications. | |
Freeze fault, air coil - low refrigerant | Check refrigerant pressure with gage set. |
CHECK | POSSIBLE CAUSE | SOLUTION |
---|---|---|
Is fault LED Blinking 1 time? | High Pressure fault - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. |
High Pressure fault - high water temperature | Check water temperature - is it in range? | |
High Pressure fault - fouled or scaled water coil | Check for proper flow rate and water temperature, but low water side temp rise in cooling. | |
Check fan motor for proper operation. | ||
Is fault LED Blinking 2 times? | High Pressure fault - no or low airflow | Check air filter. |
Inspect air coil for dirt/debris. | ||
Check ductwork - are dampers closed or blocked? | ||
Low Pressure fault - no or low airflow | Check fan motor for proper operation. | |
Check air filter | ||
Inspect air coil for dirt/debris | ||
Check ductwork - are dampers closed or blocked? | ||
Low Pressure fault - low refrigerant | Check refrigerant pressure with gage set | |
Is fault LED Blinking 3 times? | Low Pressure fault - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. |
Low Pressure fault - low refrigerant | Check for proper flow rate and water temperature, but low water side temp drop in heating. | |
Freeze fault, water coil - no or low water flow | Check water valves and/or pumps for proper operation. Check for water coil blockage. | |
Freeze fault - low water temperature | Check water temperature - is it below 40 F entering? If heat pump is connected to a closed loop with anti- freeze check that the "FREEZE 1 * resistor on the Complete C board has been cut to set the unit to anti- freeze mode. | |
Freeze fault - low refrigerant | Check refrigerant pressure with gage set | |
Blinking 4 times? | Condensate fault - poor drain- age | Check condensate pan for high water level. Check drain line for blockages, double trapping or inadequate trapping. |
Condensate fault - blocked return air | Check condensate pan for high water level. Check air filter and return air ductwork tor blockage. Check that there is adequate space between the return air opening and walls or other obstructions on free return applications. | |
Is fault LED Blinking 5 times? | Brown out fault - low supply voltage | Check primary voltage - ensure it is within the limits listed on the unit data plate. |
Brown out fault - overloaded control circuit | Check control voltage - if it is below 18 V check accessories connected to the unit and insure that they do not exceed the VA draw | |
Brown out fault - bad thermostat connection | Check that thermostat wiring is proper gage and length, that it is not damaged and that all connections at the thermostat and heat pump are secure. | |
Is fault LED Blinking 6 times? | Freeze fault, air coil - no or low airflow | Check fan motor for proper operation. |
Check air filter | ||
Inspect air coil for dirt/debris | ||
Check ductwork - are dampers closed or blocked? | ||
Freeze fault, air coil - blocked return air | Check that there is adequate space between the return air opening and walls or other obstructions on free return applications. | |
Freeze fault, air coil - low refrigerant | Check refrigerant pressure with gage set. |
FAULT | DESCRIPTION | SOLUTION |
---|---|---|
Motor rocks slightly when starting | This is normal start-up for ECM. | |
Motor will not start | No movement | Check power at motor. |
Check low voltage (24-vac R to C) at motor. | ||
Check low voltage connections (G.Y W. R. C) at motor. | ||
Check for unseated Dins in connectors on motor harness. | ||
Check motor for tight shaft. | ||
Perform motor/control replacement check. | ||
Run moisture check. | ||
Motor rocks | Check for loose or non-compliant motor mount. | |
Make sure blower wheel is tight on shaft. | ||
Perform motor/control replacement check. | ||
Motor oscillates up and down while being tested off of blower | It is normal for motor to oscillate with no load on shaft. | |
Motor starts, but runs erratically | Varies up and down or intermittent | Check line voltage for variation or “saq." |
Check law voltage connections (G,Y W, R ; C) at motor, unseated pins in motor harness connectors. | ||
Check “Bk” for erratic cfm command (in variable speed applications). | ||
Check system controls, thermostat. | ||
Perform moisture check. | ||
“Hunts" or “puffs” at high cfm (SDeed) | If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow. | |
Stays at low cfm despite system call for cool or heat cfm | Check lew voltage (thermostat) wires and connections. | |
Verity fan is not in delay mode. Wait until delay is complete. | ||
Perform motor/control replacement check. | ||
Verify fan is not in delay mode. Wait until delay is complete. | ||
Perform motor/control replacement check. | ||
Excessive noise | Noisy blower or cabinet | determine if it’s air. cabinet, duct, or motor noise. |
Check for loose blower housing. panels. etc. | ||
If high static is creating high blower speed, check for air whistling through seams in ducts, cabinets, or panels. | ||
If high static is creating high blower speed. check for cabinet/duct deformation. | ||
“Hunts" or “puffs” at high cfm (speed) | If removing panel or filter reduces '‘puffing; reduce restriction or reduce maximum airflow. | |
Evidence of moisture | Motor failure or malfunction has occurred and moisture is present | Replace motor and perform moisture check.. |
Evidence of moisture present inside air mover | Perform moisture check. |
Malfunctions | Cause | What should be done? |
---|---|---|
Unit does not start | Power cut | Wait for power to be restored. |
Unit may have become unplugged. | Check that the plug is securely in the wall receptacle. | |
Fuse may have blown. | Replace the fuse. | |
Battery in remote controller may have been exhausted. | Replace the battery. | |
The time you have set with timer is incorrect. | Wait or cancel timer setting. | |
Unit not cooling or heating (cooling/ heating models only) room very well while air flowing out from the air conditioner | Inappropriate temperature setting. | Set temperature correctly. |
Air filter is blocked. | Clean the air filter. | |
Doors or windows are open. | Close the doors or windows. | |
Air inlet or outlet of indoor or outdoor unit has been blocked. | Clear obstructions away first, then restart the unit. | |
Compressor 3 minutes protection has been activated. | Wait. |
PROBLEM | POSSIBLE CAUSE |
---|---|
Control modules do not have lights when unit power is on. | Transformer open. Circuit breaker open. Power wiring open. Module failure. |
Control display does not light up when unit power is on. | Connection location. Interface cable open. Display failure. |
Run test will not start. | Pre-existing ALARM (red)? Not ‘logged in” with password. Switch not in local. |
WARN (yellow) LED does not light during run test. | Wiring open. Lamp failure. Control module failure. |
ALARM (red) LED does not light during run test. | Wiring open. Lamp open. Control module failure. |
Run test stops, ALARM (red) LED light is lit after it blinks once. | Bypass switch to LINE. Mode switch to OFF. Duct high pressure switch open. Fire shutdown input or jumper open. |
Supply air temp out of range. Duct static pressure sensor out of range. Compressor resistor board wiring error or failure. | |
Fan does not start/ALARM (red) LED blinks 2 times. | Fan relay failure. |
Run test stop, ALARM (red) LED is lit after blinking 3 times. | Wiring open. VFD connection error. VFD setup error. Fan relay failure. Current isolator failure. Control module failure. |
Run test stop, ALARM (red) LED is lit after it blinks 4 times. Fan does not increase speed. | VFD connection error. VFD setup error. Current isolator load adjustment too low. |
Fan does not stop after ALARM (red) LED blinks 5 times. | Fan relay failure. |
Fan rotation is backwards. | VFD to motor wiring sequence error. VFD setup error. |
Run test stop, ALARM (red) LED is lit after blinking 6 times. Compressor does not start. | Wiring open. Compressor resistor board wiring error or failure. High pressure switch, low pressure switch, coil frost switch, or compressor protection module open. Compressor relay failure. Contactor failure. Control module failure. No refrigerant charge. |
Run test stop, ALARM (red) LED is lit after blinking 7 times. Compressor 2 does not start. | |
Run test stop, ALARM (red) LED is lit after blinking 8 times. Compressor 3 does not start. | |
Run test stop, ALARM (red) LED is lit after blinking 9 times. Compressor 4 does not start. | |
Compressor rotation is backwards. | Field power wiring sequence error. Compressor power wiring sequence error. |
“C” message in I/O status display. | No input signal or communication failure. |
“Service’ message in I/O status display. | Value is forced from 6400 keypad entry. |
“Supervisor" message in I/O status display. | Value is forced from network communication (i.e., PC). |
ALARM (red) LED always on, will not enter run test. | SAT, DSP, CSMUX, DHS, or PHASE input values. Mode switch OFF. |
PROBLEM | CAUSE | REMEDY |
---|---|---|
Compressor Outdoor Fan Will Not Start. | Power failure. | Call power company. |
Fuse blown or circuit breaker tripped. | Replace fuse or reset circuit breaker. | |
Defective thermostat, contactor transformer or control relay. | Replace component. | |
Insufficient line voltage. | Determine cause and correct. | |
Incorrect or faulty wiring. | Check wiring diagram and rewire correctly. | |
Thermostat setting too high. | Lower thermostat setting below room temperature. | |
High-pressure switch tripped. | ||
Low-pressure switch tripped. | Check for leaks, repair, and recharge. | |
Freeze-up protection thermostat tripped. | ||
Compressor Will Not Start But Outdoor Fan Runs. | Faulty wiring or loose connections in compressor circuit. | Check wiring and repair or replace. |
Compressor motor burned out, seized, or internal overload open. | Determine cause. Replace compressor. | |
Defective overload. | Determine cause and replace. | |
One leg of 3-phase power dead. | Replace fuse or reset circuit breaker. Determine cause. | |
Compressor Cycles (Other Than Normally Satisfying Thermostat). | Refrigerant overcharge or undercharge. | Recover refrigerant, evacuate system, and recharge to nameplate. |
Defective compressor. | Replace and determine cause. | |
Insufficient line voltage. | Determine cause and correct. | |
Blocked outdoor coil or dirty air filter. | ||
Defective overload. | Determine cause and replace. | |
Defective thermostat. | Replace thermostat. | |
Faulty outdoor-fan (cooling) or indoor-fan (heating) motor or capacitor. | Replace. | |
Restriction in refrigerant system. | Locate restriction and remove. | |
Compressor Operates Continuously. | Dirty air filter. | Replace filter. |
Unit undersized for load. | Decrease load or increase unit size. | |
Thermostat set too low. | Reset thermostat. | |
Low refrigerant charge. | Locate leak, repair, and recharge. | |
Leaking valves in compressor. | Replace compressor. | |
Air in system. | Recover refrigerant, evacuate system, and recharge. | |
Outdoor coil dirty or restricted. | Clean coil or remove restriction. | |
Dirty air filter. | Replace filter. |
NO. OF QUICK LED FLASHES | SYSTEM FAULT |
---|---|
2 | Room Air Thermistor |
3 | Indoor Coil Thermistor |
4 | Outdoor Coil Thermistor |
5 | Compressor Malfunction |
6 | Reversing Valve Malfunction |
7 | Outdoor Air Thermistor* |
8 | Indoor Fan Failure |
9 | Discharge Air Thermistor |
Error | Cool | Heat | Chek | Cause | Solution |
---|---|---|---|---|---|
Excessively warm supply air temperature in cooling and/or excessively cool air in heating | X | X | Airflow too high | Fan speed setting too high | Consult blower performance table and reduce fan speed if possible. |
High or low water temperature | Inlet water temperature out of range | Check unit capacity vs. water temperature. | |||
Air leakage | Leaky ductwork | Inspect ductwork. | |||
Loss of refrigeration capacity | Low refrigerant | Check refrigerant pressures with gage set. | |||
Excessively cold supply air temperature in cooling or excessively hot supply air temperature in heating | X | X | Reduced airflow | Dirty Filter | Replace filter. |
Fan speed too low | Consult blower performance table and increase fan speed if possible. | ||||
Excessive duct pressure drop | Consult blower performance table and increase fan speed if possible. | ||||
No compressor or fan operation | X | X | Power LED on | Bad thermostat connection / faulty thermostat | Check thermostat and wiring. "C\ |
Power LED off | Low or no supply power | Ensure that the supply voltage to the unit is with in the range shown on the unit data plate. | |||
Faulty control transformer | Check for 24 VAC between ‘R* and "C* on the unit terminal block. For 75 and 100 VA transformers, check that the transformer circuit breaker has not tripped. Check low voltage circuit for overload conditons or short circuits before replacing the transformer. | ||||
No fan operation - PSC motor | X | X | Fan relay energized | Faulty motor | Check supply voltage from the fan relay to the motor. Check that all motor wires are secure. With power off spin the motor shaft - noise, resistance or uneven motion can be signs of motor failure. |
Fan relay not energized | No fan operation signal | Check for 24 VAC across the fan relay coil. Check all wiring connections. | |||
Bad fan relay | If the relay coil is energized but the relay does not pull in, check the resistance across the relay coil - an open circuit is an indicator of a faulty relay. | ||||
No fan operation - constant torque motor | X | X | No fan operation signal | Check all wiring connections. | |
Loose wiring | Check all wiring connections at motor and control box. | ||||
Faulty motor | Check supply voltage to the motor. Check that all motor wires are secure. With power off spin the motor shaft - noise, resistance or uneven motion can be signs of motor failure. | ||||
No fan operation - constant airflow motor | X | X | No fan operation signal | Check all wiring connections. Make sure that the thermostat connection plug is securely connected. | |
Loose wiring | Check all wiring connections at motor and control box. Check that power and control harnesses are securely connected. | ||||
Interface board problems | Make sure that the interface board is not damged and that all DIP switches are in the proper configuration | ||||
Faulty motor | Check supply voltage to the motor. Check that all motor wires are secure. Move the “TEST" DIP switch to *ON* and the other switches to "OFF* on the "ADJUST" switch block on the interface board With power off spin the motor shaft - noise, resistance or uneven motion can be signs of motor failure. | ||||
Unit not shifting into cooling | X | Reversing valve solenoid energized | Faulty solenoid | Check that the reversing valve solenoid is receiving 24 VAC. If so, check the resistance of the solenoid - an open circuit may indicate a burned out solenoid. | |
Reversing valve solenoid not energized | Miswired/ faulty thermostat | Check that the reversing valve theromstat wire is connected to the “0‘ terminal of the thermostat | |||
Check that the wires from the thermostat to the unit are securely connected and that the wires from the electrical box to the reversing valve are connected. |
If Run LED shows... | And Error LED shows... | Status is... |
---|---|---|
2 flashes per second | Off | Normal |
2 flashes per second | 2 flashes, alternating with Run LED | Five minute auto-restart delay after system error |
2 flashes per second | 3 flashes, then off | Control module has just been formatted |
2 flashes per second | 4 flashes, then pause | Two or more devices on this network have the same ARC156 network address |
2 flashes per second | On | Exec halted after frequent system errors or control programs halted |
5 flashes per second | On | Exec start-up aborted, Boot is running |
5 flashes per second | Off | Firmware transfer in progress, Boot is runnin |
7 flashes per second | 7 flashes per second, alternating wit Run LED | Ten second recovery period after brownout |
14 flashes per second | 14 flashes per second, alternating with Run LED | Brownout |
On | On | Failure. Try the following solutions: |
- Turn the RTU —MP off, then on. | ||
- Format the RTU-MP. | ||
- Download memory to the RTU-MR | ||
- Replace the RTU —MP. |
FAULT | DESCRIPTION | SOLUTION |
---|---|---|
Motor rocks slightly when starting | This is normal start-up for ECM. | |
Motor will not start | No movement | Check power at motor. |
Check low voltage (24-vac R to C) at motor. | ||
Check low voltage connections (G,Y. W, R. C) at motor. | ||
Check for unseated pins in connectors on motor harness. | ||
Test with a temporary jumper between R and G. | ||
Check motor for tight shaft. | ||
Perform motor/control replacement check. | ||
Run moisture check. | ||
Motor rocks | Check for loose or non-compliant motor mount. | |
Make sure blower wheel is tight on shaft. | ||
Perform motor/control replacement check. | ||
Motor oscillates up and down while being tested off of blower | It is normal for motor to oscillate with no load on shaft. | |
Motor starts, but runs erratically | Varies up and down or intermittent | Cheek line voltage for variation or “sag.” |
Check low voltage connections (G,Y, W, R : C) at motor, unseated pins in motor harness connectors. | ||
Check “Bk” for erratic cfm command (in variable speed applications). | ||
Check system controls, thermostat. | ||
Perform moisture check. | ||
“Hunts” or “puffs” at high cfm (speed) | If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow. | |
Stays at low cfm despite system call for cool or heat cfm | Check low voltage (thermostat) wires and connections. | |
Verify fan is not in delay mode. Wait until delay is complete. | ||
Perform motor/control replacement check. | ||
Stays at high cfm | Verify fan is not in delay mode. Wait until delay is complete. | |
Perform motor/control replacement check. | ||
Blower will not shut off | Check for Triac switched thermostat or solid state relay. | |
Excessive noise | Noisy blower or cabinet | determine if it’s air, cabinet, duct, or motor noise. |
Check for loose blower housing, panels, etc. | ||
If high static is creating high blower speed, check for air whistling through seams in ducts, cabinets, or panels. | ||
If high static is creating high blower speed, check for cabinet/duct deformaton. | ||
“Hunts” or “puffs” at high cfm (speed) | If removing panel or filter reduces “puffing,” reduce restriction or reduce maximum airflow. |
Problems | Heat | Cool | Cause | Solution |
---|---|---|---|---|
Main Power Problems | X | X | Green Status LED Off | Check line voltage circuit breaker and disconnect. |
Check for line voltage between L1 and L2 on the contactor. | ||||
Check for 24 vac between R and C on controller. | ||||
Check primary/ secondary voltage on transformer. | ||||
HP Fault — Code 2 High Pressure | X | Reduced or no water flow in cooling | Check pump operation or valve operation/ setting. | |
Check water flow adjust to proper flow rate. | ||||
X | Water temperature out of range in cooling | Bring water temperature within design parameters. | ||
X | Reduced or no airflow in heating | Check for dirty air filter and clean or replace. | ||
Check fan motor operation and airflow restrictions. | ||||
Dirty air coil — construction dust etc. | ||||
External static too high. Check Tables 8-11. | ||||
X | Air temperature out of range in heating | Bring return-air temperature within design parameters. | ||
X | X | Overcharged with refrigerant | Check superheat/ subcooling vs typical operating condition | |
X | X | Bad HP switch | Check switch continuity and operation. Replace. | |
LP/LOC Fault — Code 3 Low Pressure/ Loss of Charge | X | X | Insufficient charge | Check for refrigerant leaks. |
X | Compressor pump down at start-up | Check charge and start-up water flow. | ||
FP1 Fault — Code 4 Water Freeze Protection | X | Reduced or no water flow in heating | Check pump operation or water valve operation/ setting. | |
Plugged strainer or filter. Clean or replace. | ||||
Check water flow adjust to proper flow rate. | ||||
X | Inadequate antifreeze level | Check antifreeze density with hydrometer. | ||
X | Improper freeze protect set- ting (30 F vs 10 F) | Clip JW2 jumper for antifreeze (10 F) use. | ||
X | Water temperature out of range | Bring water temperature within design parameters. | ||
X | X | Bad thermistor | Check temperature and impedance correlation. | |
FP2 Fault — Code 5 Air Coil Freeze Protection | X | Reduced or no airflow in cooling | Check for dirty air filter and clean or replace. | |
Check fan motor operation and airflow restrictions. | ||||
External static too high. | ||||
X | Air temperature out of range | Too much cold vent air. Bring entering-air temperature within design parameters. | ||
X | Improper freeze protect set- ting (30 F vs 10 F) | Normal airside applications will require 30 F only. | ||
X | X | Bad thermistor | Check temperature and impedance correlation. | |
Condensate Fault — Code 6 | X | X | Blocked drain | Check for blockade and clean drain. |
X | X | Improper trap | Check trap dimensions and location ahead of vent. | |
x | Poor drainage | Check for piping slope away from unit. | ||
Check slope of unit toward outlet. | ||||
Poor anting. Check vent location. | ||||
x | Moisture on sensor | Check for moisture shorting to air coil. | ||
Over/ Under Voltage — Code 7 (Auto Resetting) | x | x | Under voltage | Check power supply and 24 vac voltage before and during operation. |
Check power supply wire size. | ||||
Check compressor starting. | ||||
Check 24 vac and unit transformer tap for correct power supply voltage. | ||||
x | x | Over voltage | Check power supply voltage and 24 vac before and during operation. | |
Check 24 vac and unit transformer tap for correct power supply voltage. | ||||
Performance Monitor — Code 8 | x | Heating mode FP2>125 F | Check for poor airflow or overcharged unit. | |
x | Cooling mode FP1>125 F OR FP2 | Check for poor water flow or airflow. |