Rheem R802VA07542117MSA Error Code A093_F: Internal Control Fault Detected
What Does Code A093_F Mean?
Fault code A093_F on the Rheem R802VA indicates that the IFC board has detected an unspecified internal fault that has caused a hard lockout. This is one of the most severe fault conditions the furnace can report. A hard lockout means the furnace will not restart automatically — power must be cycled off and back on only after the underlying fault has been corrected.
The IFC also sets A093_F when voltage is detected unexpectedly on the gas valve contacts and this voltage does not go away when the inducer is shut off, which would indicate a welded relay on the control board. A welded gas valve relay is a safety concern because it means the control board cannot interrupt power to the gas valve, potentially allowing gas to flow when it should not.
For a general internal fault, the control board's own electronics have experienced a failure condition that the self-diagnostic system detected but cannot specifically identify. Power surges, internal component failures, or long-term degradation can cause this. In either scenario — welded relay or general internal fault — the control board will almost certainly need to be replaced by a qualified technician.
Common Causes
When to Call a Professional
Contact a licensed HVAC technician if:
- Any time this code appears — this is a hard lockout requiring professional diagnosis before the furnace is restarted
- If a welded gas valve relay is the cause, shut off the manual gas supply valve immediately and call a technician
- The control board requires professional evaluation and likely replacement; do not continue operating the furnace until it has been serviced
✓ Verified against manufacturer service manual — March 2026