Rinnai Water Heater Error Code 26: How to Fix It

Q: What does error code 26 mean on a Rinnai water heater?

Error code 26 indicates a bypass servo fault. The bypass servo valve controls water flow to maintain temperature, and the error means it is disconnected malfunctioning.

Q: Can I still use my Rinnai water heater with error code 26?

No. The unit will typically shut down or limit operation. Continuing to use it may cause inconsistent temperatures or further damage. Fix it before use.

Q: Where is the bypass servo valve located on a Rinnai tankless water heater?

It is located inside the front cover, often near the water inlet manifold. It has wires and small water lines attached.

Q: How much does it cost to replace a bypass servo valve?

The part typically costs $50-$100. If you have it professionally replaced, labor may add $100-$200.

Q: What causes a bypass servo fault on a Rinnai water heater?

Common causes include a stuck valve due to debris, a failed servo motor, or a loose electrical connection.

Abstract

Error code 26 on a Rinnai tankless water heater indicates a bypass servo fault. The bypass servo valve regulates water flow to maintain temperature, and this error means the valve or its motor has failed or is stuck. This guide will help you diagnose and resolve the issue.