Rinnai Water Heater Error Code 33: How to Fix It

Q: What causes Rinnai error code 33?

Error code 33 is caused by a faulty heat exchanger temperature sensor that either provides incorrect temperature readings or fails to communicate with the control board. This can result from sensor aging, electrical connection problems, or physical damage to the sensor.

Q: Can I still use my Rinnai water heater with error code 33?

No, you should not use the water heater when error code 33 is displayed. This safety feature prevents the unit from operating when it cannot accurately monitor heat exchanger temperature, which could lead to overheating or other dangerous conditions.

Q: How much does it cost to fix Rinnai error code 33?

The cost typically ranges from $50-150 if you replace the temperature sensor yourself, or $200-400 if you hire a professional technician. The sensor part usually costs $30-80, with labor making up the difference in professional repairs.

Q: How long do Rinnai temperature sensors last?

Rinnai temperature sensors typically last 8-12 years under normal operating conditions. Factors like water quality, usage frequency, and maintenance can affect sensor lifespan. Regular maintenance can help extend sensor life.

Q: Will error code 33 clear itself?

Error code 33 will not clear itself if there's an actual sensor fault. While a system reset might temporarily clear the code, it will return if the underlying sensor problem persists. The sensor or its connections need to be repaired or replaced to permanently resolve the error.

Abstract

Rinnai error code 33 indicates a heat exchanger temperature sensor fault, which means the sensor that monitors the temperature of your water heater's heat exchanger is malfunctioning or providing incorrect readings. This error prevents your water heater from operating safely and requires prompt attention to restore hot water service.