Rinnai Tankless Water Heater Error Code 10: How to Fix It

Q: What does error code 10 mean on a Rinnai water heater?

Error code 10 indicates an air supply or exhaust blockage. The heater has detected restricted airflow in the vent system or intake, causing a safety shutdown.

Q: Can I still use hot water with error code 10?

No. The heater will not operate when error 10 is active. Attempting to bypass the safety shutdown can lead to carbon monoxide poisoning or fire.

Q: How do I clear a blocked exhaust vent?

Turn off power and gas. Visually inspect the vent pipe for obstructions like leaves, nests, or ice. Remove any blockages by hand or with a brush. Ensure the vent termination outside is not blocked.

Q: Why does my Rinnai keep showing error 10 after cleaning the vents?

Possible causes include a hidden blockage, a faulty pressure switch, a blocked secondary heat exchanger, or improper vent length. Contact a professional for further diagnosis.

Q: Is error code 10 dangerous?

Yes. It signals a venting issue that can cause carbon monoxide to enter your home. If you see this error, address it immediately and ensure the vent system is clear.

Abstract

Error code 10 on your Rinnai tankless water heater indicates an air supply or exhaust blockage. This means the unit cannot properly vent combustion gases or draw in fresh air, triggering a safety shutdown. It's a serious issue that requires immediate attention to prevent carbon monoxide buildup or damage to the heater.