Rheem R96VA0702317MSA Error Code 93: Internal Control Fault Detected
What Does Code 93 Mean?
A code 93 on the Rheem R96VA0702317MSA is a severe and rare fault indicating a critical internal failure in the integrated furnace control board. This code can represent one of two conditions: an internal microprocessor fault detected by the IFC's self-diagnostic routines, or unexpected voltage detected at the main gas valve solenoid when the IFC has not commanded the valve to open. Both conditions are serious and should rarely occur in a properly installed and maintained furnace.
When code 93 is triggered during a heating call, the gas valve closes immediately, all outputs are de-energized, and the furnace shuts down. The IFC may display codes 93 and 10 alternately, indicating the severe fault has also pushed the furnace into soft lockout. This lockout cannot be cleared by simply cycling the thermostat — the underlying fault must be addressed first.
The most likely cause is a failed IFC control board that needs replacement. Mis-wiring that sends 24-volt AC to the gas valve solenoid circuit when it should not be present can also trigger this code, though wiring faults are less common. A technician should first check for any obvious wiring anomalies at the gas valve solenoid connection before condemning the IFC. If wiring is correct, the IFC board requires replacement with the correct part for the R96VA0702317MSA.
Common Causes
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician immediately — code 93 indicates a severe internal control fault that requires professional diagnosis, and the furnace will not operate until the IFC is inspected and likely replaced
- The technician should first check all wiring at the gas valve solenoid for unexpected 24VAC connections before replacing the IFC control board with the correct model-specific part
✓ Verified against manufacturer service manual — March 2026