What It Means
Internal control board microprocessor fault.
Rheem AC & Heat Pump
Rheem AC & Heat Pump Error Code 93
Troubleshooting guide for the Rheem AC & Heat Pump system fault 93.
Possible Causes
- Control board internal component failure.
- Corrupted memory or firmware.
- Wiring fault or power surge damage.
Not sure which one it is — or if it's none of these? Try ACLogics today.
Disclaimer: This information is for general reference. Error codes can vary by model and production year. Always refer to your machine's specific manual and the information printed on the unit itself.
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Full Diagnosis
Internal control fault.
All Recorded Causes
Outdoor control board/internal control malfunction, corrupted control logic, wiring fault, or failed ICC/control board. Cycle power only after checking safety and wiring; replace board if the fault returns.
Verify Before Replacing Parts
- Confirm the exact Rheem model family and ac and heat pump context before acting on a generic code description.
- Start with line voltage, low voltage, and board output checks in sequence so the fault is isolated cleanly — the data plate flags outdoor control board/internal control malfunction, corrupted control logic, wiring fault,….
- Inspect connectors, relay outputs, and any recently replaced electrical parts for mismatch or loose fit, and verify cycle power only after checking safety and wiring; replace board if the fault returns.
- After the correction, run the system long enough to confirm the ac and heat pump fault does not return under normal load.
Not sure which system this Rheem code is on?
ACLogics has guided diagnostics for 57 Rheem fault codes and asks the right questions to narrow it down.
