Rinnai Water Heater Error Code 29: How to Fix It

Q: Can I reset Rinnai error code 29 myself?

You can try resetting the unit by turning off power for 1 minute and turning it back on. However, if the freeze damage is severe, the error will return. A reset does not fix the underlying damage.

Q: How do I prevent freeze damage on my Rinnai water heater?

Install the unit in a location that does not drop below freezing. Use freeze protection features (e.g., internal heaters) if available, and insulate exposed pipes. Some models have a built-in winterization mode.

Q: Is error code 29 covered under warranty?

Typically, freeze damage is considered environmental and may not be covered by the standard warranty. Check your warranty terms or contact Rinnai for clarification.

Q: What parts are most likely damaged with freeze damage?

The heat exchanger is most vulnerable to cracking. Other possible damaged parts include the water flow sensor, inlet/outlet pipes, and internal seals.

Q: How much does it cost to repair freeze damage on a Rinnai heater?

Repair costs vary widely, from $100-200 for minor sensor replacement to $500-1000+ for heat exchanger replacement. In severe cases, replacement of the entire unit may be more cost-effective.

Abstract

Error code 29 on your Rinnai tankless water heater indicates freeze damage has occurred internally. This critical error means water may have frozen inside the unit, potentially cracking heat exchangers or pipes. Immediate shutdown and professional assessment are often required to prevent further damage and safety hazards.