Noritz error code 71: gas valve circuit problem

Code 71 is less about the gas valve itself and more about the electronics driving it. Noritz's knowledge base points first to the quality of the power reaching the heater.

The meaning below comes from Noritz's own technical knowledge base. Noritz technical support: 866-766-7489.

Common causes

• Battery backup or solar power whose inverter does not produce a pure sine wave. The circuit board cannot work properly on that power.
• A shared electrical circuit. An appliance on the same circuit, such as an old refrigerator or freezer, can create interference when its compressor cycles.
• A failed circuit board, if nothing about the electrical setup has changed.
• A failed gas valve or solenoid, which a technician can test with a meter.

What you can check

1. Ask whether a battery backup, generator or solar system was added recently.
2. If safe and practical, plug the heater into a different outlet on a different circuit. Noritz says that if code 71 goes away, the original circuit was the problem.
3. If nothing has changed, call a technician to test the board and valve.

How to reset it

Turn the heater off at the remote controller and back on. If the code stays, disconnect the unit's electrical power for about 30 seconds, then restore it. If the code comes straight back, the cause is still there.

Before you call

Have the model and serial number from the rating label ready, along with the exact code and when it appears: at startup, during use, or only at high demand. Mention any recent work on the gas, water or electrical supply and when the heater was last serviced. This helps the technician bring the right parts and often saves a second visit.

See every code on our Noritz error codes page.