In this blog, we are providing a comprehensive list of Rheem air conditioner error codes and their meanings. These error codes are essential for diagnosing and resolving issues with your Rheem air conditioner quickly and effectively.
By understanding these codes, you can save time and money on costly repairs and replacements. Whether you’re a homeowner or a technician, this information is valuable for keeping your Rheem air conditioner running smoothly and efficiently.
Rheem Air Conditioner Error Codes List
| ERROR CODES | DESCRIPTION | CAUSE |
| 0- Standby | No command for unit run | Normal run |
| c – First Stage Cooling | The unit has received a command for the first stage cooling | Normal run |
| c Flashing | Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active | · The unit has received a command for first-stage cooling during an active anti-short cycle timer or minimum run timer.
· Wait until the unit timer has expired or press the TEST button to defeat the short cycle delay. |
| C – Second Stage Cooling | The unit has received a command for the second stage cooling | Normal run |
| C Flashing | Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active | · The unit has received a command for second-stage cooling during an active anti-short cycle timer or minimum run timer.
· Wait unit timer has expired or press the TEST button to defeat the short cycle delay. |
| h – First Stage Heat Pump | The unit has received a command for the first stage heat pump | Normal run |
| h Flashing | Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) action | · The unit has received a command for the first stage heat pump during an active anti-short cycle timer or minimum run time
· Wait unit timer has expired or press the TEST button to defeat the short cycle delay |
| H – Second Stage Heat Pump | The unit has received a command for the second stage heat pump | Normal run |
| H Flashing | Anti-short cycle timer (3 minutes) or Minimum run timer (30 seconds) active | · The unit has received a command for a second stage heat pump during an active anti-short cycle timer or minimum run timer.
· Wait unit timer has expired or press the TEST button to defeat the short cycle delay |
| d – Defrost Active | The unit is undergoing a defrost cycle | Normal run |
| t – Test Mod | Test Mod | The ICC is in TEST mode |
| P – Protector Trip | A command for the compressor run is present, but no current is measured to the compressor | Motor protector open |
| 01 – Long Run Time (Compressor) | The compressor has continuously run for more than 18 hours in the cooling mode. | · Low refrigerant charge
· Air ducts have substantial leakage · Dirty indoor air filter · Dirty outdoor coil |
| 02 – High Pressure | Compressor limit has opened four (4) times within a call for run | ·The outdoorr coil is dirty (cooling mode)
· The outdoor fan is not running (cooling mode) · Dirty indoor coil or filter (heating mode) · Indoor blower is not running (heating mode) · Liquid line restriction · Excessive refrigerant charge |
| 03 – Short Cycling | ICC detects that the run time for the past four (4) compressors or cycles is less than three (3) minutes each | · Test thermostat wire connection
· Test thermostat location inthe zone |
| L4 – Locked Rotor | The ICC detects that four (4) consecutive protector trips have occurred, and the average run time for each trip is less than 15 seconds | · Bad run capacitor
· Low line voltage · Excessive refrigerant inthe compressor · Seized bearings in the compressor |
| 05 – Open circuit (Compressor will not Run) | The ICC has had a protector trip for longer than 4 hours | · Test for damaged, wrong connection, or wrong run capacitor
· Test for broken Wires, loose connectors, or wrong connection compressor · Test compressor windings for continuity · Test for open compressor internal protector |
| 06 – Compressor Open Start Circuit | The ICC detects current in the Run circuit but not in the Start circuit of the compressor | · Test for damaged, wrong connection, or wrong run capacitor
· Test for broken Wires, loose connectors, or wrong connection compressor · Test compressor windings for continuity |
| L6 – Compressor Open Start Circuit | The ICC detects current in the Run circuit but not in the Start circuit of the compressor four (4) times in one compressor call | · Test for damaged, wrong connection, or wrong run capacitor
· Test for broken Wires, loose connectors, or wrong connection compressor · Test compressor windings for continuity |
| 07 – Compressor Open Run Circuit | The ICC detects current in the Start circuit but not in the Run circuit of the compressor | · Test for damaged, wrong connection, or wrong run capacitor
· Test for broken Wires, loose connectors, or wrong connection compressor · Test compressor windings for continuity |
| L7 – Compressor Open Run Circuit | The ICC detects current in the Start circuit but not in the Run circuit of the compressor four (4) times in one compressor call | · Test for damaged, wrong connection, or wrong run capacitor
· Test for broken Wires, loose connectors, or wrong connection compressor · Test compressor windings for continuity |
| 09 – Low Secondary Volts | The secondary voltage at R and C is below 18VAC | · Control transformer overloaded
· Low line voltage |
| 21 – Low Pressure Control Open | The ICC detects that the LPC is open. Note: The low-pressure control is ignored for the first 90 seconds of compressor run | · The unit has a low refrigerant charge
· Indoor coil is frozen (cooling mode) · Dirty indoor coil or filter (cooling mode) · Indoor blower is not running (cooling mode) · The outdoor coil is frozen (heating mode) · The expansion valve is not operating correctly |
| L21 Flashing | Active Protection, Low Pressure Control Trip | LPC has opened 3 times in the same cooling run, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 21. |
| 27 | Low Line Voltage or No Line Voltage Fault | · Test the incoming line voltage to the disconnect and unit
· Test wiring connections |
| 28 | High Line Voltage Fault | Test the line voltage |
| 29 | High Pressure Control Open. The ICC detects that the HPC is open | · The outdoor coil is dirty (cooling mode)
· The outdoor fan is not running (cooling mode) · Dirty indoor coil or filter (heating mode) · Indoor blower is not running (heating mode) · Liquid line restriction · Excessive refrigerant charge |
| L29 Flashing – Active Protection | High Pressure Control Trip | LPC has opened 3 times in the same cooling run, the ICC has locked out the compressor to protect it. ICC alternately flashes L and 29 |
| 30 – Fuse Open | The ICC detects that the on—onboard fuse is open | · The 3—amp fuse on the ICC is open.
· Low voltage Wiring at R and C is damaged or a wring connection. |
| 80 – Low Air Flow | The ICC detects that the indoor unit is not providing the minimum airflow requirements. | Misapplied wrong indoor air mover – replace with a properly sized unit. |
| 83 – Condenser Coil Temperature Fault | The sensor detects an abnormally low or high coil temperature | · Replace the sensor
· Test sensor is installed correctly on the control |
| 84 – Outdoor Ambient Temperature Fault | The sensor detects an abnormally low or high outdoor ambient temperature | · Test unit placement – If the outdoor unit is in a high-temperature area, wait until the ambient temperature drops and test the sensor reading.
· Replace the sensor. · Test sensor is installed correctly on the control |
| 93 – Internal Control Fault | The control is not functioning properly. | · Test control for proper system Run.
· Replace control |
| d1 | No Shared Data | Replace the memory card with the correct system information. |
| d3 – Airflow CFM Mismatch | The indoor air mover (air handler/furnace) cannot supply the required airflow for proper system run. | Misapplied wrong indoor air mover- replace with a properly sized air handler/furnace. |
| d4 – (Device) Memory Card Invalid for Device | The data in the memory card inserted into the control board does not match the data in the control. | · Test the memory card to ensure it matches the device
· Test if memory card is present |
| d8 – Old Shared Data | System data is obsolete | If the system will not operate, order a new memory card to update the system information. |
| E1 | Error ee prom |
| E2 | communication failure |
| E3 | Fan-uncontrolled evaporator |
| E5 | open & short room sensor Problem |
| E6 | Open the evaporator temperature sensor |
| EC | refrigerant gas leak. |
| E2 | room temperature sensor Problem |
| E3 | coil sensor Problem of the evaporator |
| E4 | Abnormality of the outdoor unit evaporator coil sensor |
| E5 | Fan motor no power supply |
| E6 | protection signal for lack of energy. |
| E7 | Miscommunication between units |
| E8 | overheating protection. |
| DF | freezing indication, cold-protection indication: image of a propeller fan stopped |
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Rheem AC ICC Codes
Descriptions of the ICC codes are provided below: NOTE: Codes must be read from correct side to avoid an error in reading codes.
Rheem AC ICC Codes
Electrical Tests Flowchart
Thermostat Call for Cooling, No Cooling
Rheem AC Electrical Tests Flowchart
Troubleshooting
Rheem AC Troubleshooting
Disconnect all power to the unit before servicing. The contactor may break only one side. Failure to shut off power can cause an electrical shock, resulting in personal injury or death.
SYMPTOM:The Unit will not run
CAUSE:
- Power off or a loose electrical connection
- Thermostat out of calibration – set too high
- Defective control board
- Blown fuses/tripped breaker
- Transformer defective
- High-pressure control open/Low-pressure control open
- Miswiring of communications
SOLUTION:
- Test for correct voltage at line voltage connections in the condensing unit.
- Test the control board
- Replace fuses/reset breaker.
- Test wiring. Replace the transformer.
- Also, see the high head pressure Solution. The high-pressure control opens at 610 PSIG.
- Test the communication wiring
SYMPTOM: Outdoor fan runs, compressor doesn’t
CAUSE:
- Run or start capacitor is defective
- Contactor defective
- Loose connection
- Compressor stuck, grounded or open motor winding, open internal overload.
- Low-voltage condition
SOLUTION:
- Test for the correct voltage at the compressor. Test and tighten all connections.
- Wait at least 3 hours for the overload to reset. If still open, replace the compressor.
- Add start kit components.
SYMPTOM: Insufficient cooling
CAUSE:
- Improperly sized unit
- Improper indoor airflow
- Incorrect refrigerant charge
- Air, incondensable, or moisture in the system
- Bad ID TXV
SOLUTION:
- Recalculate load.
- It should be approximately 400 CFM per ton.
- The charge per procedure is attached to the unit service panel.
- Recover refrigerant. Evacuate and recharge. Add a filter dryer.
- Replace TXV
SYMPTOM: Compressor short cycles
CAUSE:
- Incorrect voltage
- Defective overload protector
- Refrigerant undercharge
SOLUTION:
- At compressor terminals, voltage must be ± 10% of the nameplate marking when the unit is operating.
- Test for correct voltage.
- Add refrigerant.
SYMPTOM: Registers sweat
CAUSE: Low indoor airflow
SOLUTION: Increase the speed of the blower or reduce the restriction. Replace the air filter
SYMPTOM: High head, low vapor pressures
CAUSE:
- Restriction in the liquid line, expansion device, or filter drier
- Bad TXV
SOLUTION:
- Remove or replace the defective component.
- Replace TXV
SYMPTOM: High head, high or normal vapor pressure – Cooling mode
CAUSE:
- Dirty outdoor coil
- Refrigerant overcharge
- The outdoor fan is not running
- Air or incondensable in the system
SOLUTION:
- Clean coil.
- Correct system charge.
- Repair or replace.
- Recover refrigerant. Evacuate and recharge
SYMPTOM: Low head, high vapor pressures
CAUSE:
- Bad TXV
- Bad compressor
SOLUTION:
- Replace TXV.
- Replace compressor
SYMPTOM: Low vapor, cool compressor, iced indoor coil
CAUSE:
- Low indoor airflow
- Operating below 65°F outdoors
- Moisture in the system
- Closed ID circuit
SOLUTION:
- Increase the speed of the blower or reduce the restriction. Replace the air filter.
- Add Low Ambient Kit.
- Recover refrigerant. Evacuate and recharge. Add a filter dryer.
- Repair or replace ID coil
SYMPTOM: High vapor pressure
CAUSE:
- Excessive load
- Defective compressor
SOLUTION:
- Retest load calculation.
SYMPTOM: Fluctuating head and vapor pressures
CAUSE:
- TXV hunting
- Air or incondensable in the system
SOLUTION:
- Test the TXV bulb clamp. Test the air distribution on the coil. Replace TXV.
- Recover refrigerant. Evacuate and recharge.
SYMPTOM: Gurgle or pulsing noise at the expansion device or the liquid line
CAUSE: Air or incondensable in the system
SOLUTION: Recover refrigerant. Evacuate and recharge.
Tips
Thank you for reading our blog on Rheem air conditioner error codes. We hope that this information has helped diagnose and resolve any issues with your Rheem air conditioner. By understanding these error codes, you can identify the source of the problem and take the appropriate steps to fix it, whether it’s through simple maintenance or by seeking the help of a qualified technician.
Remember, regular maintenance is key to preventing errors and prolonging the lifespan of your Rheem air conditioner. If you have any questions or concerns about your Rheem air conditioner, please don’t hesitate to contact a professional for assistance. Thanks again for choosing our blog as your resource for Rheem air conditioner error codes.
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