Rheem HVAC Error Code 25: How to Fix It

Q: What does error code 25 mean on a Rheem HVAC system?

Error code 25 on a Rheem HVAC system indicates an EEPROM fault. The EEPROM is a small memory chip on the control board that stores the system's operating parameters and settings. When this memory fails or becomes corrupted, the system cannot function properly and triggers the code 25 alert.

Q: Can I reset Rheem error code 25 myself?

Yes, you can attempt a hard reset by turning off the circuit breaker for the HVAC system, waiting 5 minutes, and restoring power. This clears a temporary EEPROM glitch. However, if the code returns after the reset, the control board likely has a hardware failure and will need to be replaced — which is best handled by a professional.

Q: Will Rheem error code 25 stop my heat or air conditioning from working?

Yes, in most cases an EEPROM fault will cause the system to lock out heating or cooling operations as a safety and protection measure. The system cannot trust its own stored settings or programming when the memory chip is faulty, so it shuts down to prevent further damage.

Q: How much does it cost to fix Rheem HVAC error code 25?

If the fix is simply a power reset, the cost is nothing. If the control board needs replacement, the part itself typically costs between $100 and $350 depending on the model, plus $75–$150 per hour in labor if you hire a technician. Total repair costs usually range from $200 to $600 for a professional control board replacement.

Q: What causes EEPROM faults on Rheem HVAC control boards?

The most common causes include power surges or voltage spikes from lightning or grid fluctuations, prolonged low voltage from a weak transformer or aging wiring, moisture or condensation inside the unit reaching the control board, age-related component degradation, and in rarer cases, a manufacturing defect in the board itself.

Abstract

Rheem HVAC error code 25 signals an EEPROM (Electrically Erasable Programmable Read-Only Memory) fault on the control board, meaning the board cannot properly read or write to its internal memory chip. This fault can cause your system to behave erratically, fail to start, or lock out heating and cooling functions entirely. In many cases a power reset clears the fault, but a persistent code 25 usually points to a corrupted or failed control board that will need to be replaced.