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Rheem A/C Error Codes

Rheem Error Code What this means How to fix it
Error Code 0 Unit is on standby and operating normally. Normal operation.
Error Code C Unit is operating normally and in a cooling stage. Normal operation.
Error Code Flashing C Cooling was commanded during an active anti-short cycle. Wait until unit timer has expired or press the TEST button to defeat short cycle delay.
Error Code D1 No shared data. Replace memory card with correct system information.
Error Code D3 Airflow mismatch. Replace with properly sized air handler.
Error Code D4 Memory card in control board is invalid. Check if memory card is present and ensure it matches device.
Error Code D8 Old shared data system data is obsolete. If system will not operate, order new memory card to update system information.
Error Code T Unit is in test mode.
Error Code P There's no current going to the compressor. Check to see if the motor protector is open or line voltage is disconnected.
Error Code 1 The compressor is running continuously. Check to see if there is low refrigerant, air duct leakage, a dirty outdoor coil, or a dirty air filter.
Error Codes 02, 29, and flashing L29 High-pressure problem. Check if there is a dirty outdoor coil, outdoor fan is not running, liquid line restriction, or excessive refrigerant charge.
Error Code 03 Unit is short-cycling. Check thermostat wire connections (R. C. 1. & 2) and thermostat location in zone (too close to discharge grill).
Error Codes 05, 06, 07, L6, and L7 Problem with the compressor because of an open circuit. Check for damaged, miswired. or wrong run capacitor, broken wires, loose connectors, or miswired compressor, compressor windings for continuity, and open compressor internal protector.
Error Codes L4 The rotor is locked. Check if there is a bad run capacitor, low line voltage, excessive refrigerant in compressor, or seized bearings in compressor.
Error Code 09 Secondary voltage is low. Check if the control transformer is overloaded or for low line voltage.
Error Codes 21 and flashing L21 Low-pressure control is open. Check if unit has low refrigerant charge, indoor coil is frozen, dirty indoor coil or filter, indoor blower is not running, or expansion valve is not operating correctly.
Error Code 27 Low or no line voltage. Check incoming line voltage to the disconnect and unit and wiring connections.
Error Code 28 High line voltage fault. Check line voltage.
Error Code 30 On-board fuse is open. Check if low voltage wiring at R and C is damaged or miswired.
Error Code 80 Unit isn't meeting minimum airflow requirements. Replace with properly sized unit.
Error Code 83 Problem with the condenser coil temperature. Check sensor is installed correctly on control and replace the sensor.
Error Code 84 Problem with the outdoor ambient temperature fault. Check unit placement. If the outdoor unit is in a high temperature area, wait until the ambient temperature drops and check sensor reading. Check sensor is installed correctly on control. Replace the sensor.
Error Code 93 There's a problem with the internal control. Check control for proper system operation. Replace control.
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