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	Unit has received a command for 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 unit timer has expired or press the TEST button to defeat short cycle delay.
C – Second Stage Cooling	Unit has received a command for 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 short cycle delay.
h – First Stage Heat Pump	Unit has received a command for 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 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 short cycle delay
H – Second Stage Heat Pump	Unit has received a command for 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 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 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 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	· Outdoor coil is dirty (cooling mode) · 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 the run time for the past four (4) compressor or cycles is less than three (3) minutes each	· Test thermostat wire connection · Test thermostat location in zone
L4 – Locked Rotor	The ICC detects 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 in compressor · Seized bearings in compressor
05 – Open circuit (Compressor Will not Run)	The ICC has had a protector trip for longer than 4 hours	· Test for damaged, wring connection, or wrong run capacitor · Test for broken Wires, loose connectors, or wring 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, wring connection, or wrong run capacitor · Test for broken Wires, loose connectors, or wring 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, wring connection, or wrong run capacitor · Test for broken Wires, loose connectors, or wring 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, wring connection, or wrong run capacitor · Test for broken Wires, loose connectors, or wring 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, wring connection, or wrong run capacitor · Test for broken Wires, loose connectors, or wring 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 the LPC is open. Note: The low-pressure control is ignored for the first 90 seconds of compressor run	· Unit has low refrigerant charge · Indoor coil is frozen (cooling mode) · Dirty indoor coil or filter (cooling mode) · Indoor blower is not running (cooling mode) · Outdoor coil is frozen (heating mode) · 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 incoming line voltage to the disconnect and unit · Test wiring connections
28	High Line Voltage Fault	Test line voltage
29	High Pressure Control Open. The ICC detects the HPC is open	· Outdoor coil is dirty (cooling mode) · 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 the on—board fuse is open	· The 3—amp fuse on the ICC is open. · Low voltage Wiring at R and C is damaged or 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 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 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 sensor reading. · Replace the sensor. · Test sensor is installed correctly on control
93 – Internal Control Fault	The control is not functioning properly.	· Test control for proper system Run. · Replace control
d1	N0 Shared Data	Replace memory card with 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 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 memory card to ensure it matches device · Test if memory card is present
d8 – Old Shared Data	System data is obsolete	If system Will not operate, order new memory card to update system information.

 

E1	Error ee prom
E2	communication failure
E3	Fan uncontrolled evaporator
E5	open & short room sensor Problem
E6	open evaporator temperature sensor
EC	refrigerant gas leak.
E2	room temperature sensor Problem
E3	coil sensor Problem of 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 unit before servicing. Contactor may break only one side. Failure to shut off power can cause electrical shock resulting in personal injury or death.

SYMPTOM: Unit will not run

 CAUSE:

1. Power off or loose electrical connection
2. Thermostat out of calibration – set too high
3. Defective control board
4. Blown fuses/tripped breaker
5. Transformer defective
6. High-pressure control open/Low-pressure control open
7. Miswiring of communications

SOLUTION:

1. Test for correct voltage at line voltage connections in condensing unit.
3. Test control board
4. Replace fuses/reset breaker.
5. Test wiring. Replace transformer.
6. Also see high head pressure Solution. The high-pressure control opens at 610 PSIG.
7. Test communication wiring

SYMPTOM: Outdoor fan runs, compressor doesn’t

 CAUSE:

1. Run or start capacitor defective
2. Contactor defective
3. Loose connection
4. Compressor stuck, grounded or open motor winding, open internal overload.
5. Low-voltage condition

SOLUTION:

3. Test for correct voltage at compressor. Test and tighten all connections.
4. Wait at least 3 hours for overload to reset. If still open, replace the compressor.
5. Add start kit components.

SYMPTOM: Insufficient cooling

 CAUSE:

1. Improperly sized unit
2. Improper indoor airflow
3. Incorrect refrigerant charge
4. Air, incondensable, or moisture in system
5. Bad ID TXV

SOLUTION:

1. Recalculate load.
2. Should be approximately 400 CFM per ton.
3. Charge per procedure attached to unit service panel.
4. Recover refrigerant. Evacuate and recharge. Add filter drier.
5. Replace TXV

SYMPTOM: Compressor short cycles

 CAUSE:

1. Incorrect voltage
2. Defective overload protector
3. Refrigerant undercharge

SOLUTION:

1. At compressor terminals, voltage must be ± 10% of nameplate marking when unit is operating.
2. Test for correct voltage.
3. Add refrigerant.

SYMPTOM: Registers sweat

 CAUSE: Low indoor airflow

SOLUTION: Increase speed of blower or reduce restriction. Replace air filter

SYMPTOM:  High head, low vapor pressures

 CAUSE:

1. Restriction in liquid line, expansion device, or filter drier
2. Bad TXV

SOLUTION:

1. Remove or replace defective component.
2. Replace TXV

SYMPTOM:  High head, high or normal vapor pressure – Cooling mode

 CAUSE:

1. Dirty outdoor coil
2. Refrigerant overcharge
3. Outdoor fan not running
4. Air or incondensable in system

SOLUTION:

1. Clean coil.
2. Correct system charge.
3. Repair or replace.
4. Recover refrigerant. Evacuate and recharge

SYMPTOM:  Low head, high vapor pressures

 CAUSE:

1. Bad TXV
2. Bad compressor

SOLUTION:

1. Replace TXV.
2. Replace compressor

SYMPTOM:  Low vapor, cool compressor, iced indoor coil

 CAUSE:

1. Low indoor airflow
2. Operating below 65°F outdoors
3. Moisture in system
4. Closed ID circuit

SOLUTION:

1. Increase speed of blower or reduce restriction. Replace air filter.
2. Add Low Ambient Kit.
3. Recover refrigerant. Evacuate and recharge. Add filter drier.
4. Repair or replace ID coil

SYMPTOM: High vapor pressure

 CAUSE:

1. Excessive load
2. Defective compressor

SOLUTION:

1. Retest load calculation.

SYMPTOM: Fluctuating head and vapor pressures

 CAUSE:

1. TXV hunting
2. Air or incondensable in system

SOLUTION:

1. Test TXV bulb clamp. Test air distribution on coil. Replace TXV.
2. Recover refrigerant. Evacuate and recharge.

SYMPTOM: Gurgle or pulsing noise at expansion device or liquid line

 CAUSE: Air or incondensable in 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 been helpful in diagnosing and resolving 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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