If the pilot light on your gas water heater won’t stay lit, or the water heater keeps shutting off unexpectedly, a failing thermopile could be the problem. The thermopile is an important component of the pilot assembly that generates the electrical voltage needed to keep the gas control valve operating.
When a thermopile starts to fail, it may not produce enough voltage to keep the pilot light burning. Fortunately, on some gas water heaters, the thermopile can be replaced without replacing the entire burner assembly.
In the video below, we’ll walk you through replacing the thermopile on a gas water heater, from removing the burner assembly to installing the new component. You’ll see how the pilot assembly comes apart, how the thermopile is secured in place, and how to properly reinstall everything.
We’ll also cover some of the details that can make this repair tricky, including getting the burner assembly properly positioned, lining up the manifold door, and reconnecting the wiring and gas lines. These small details are important for getting everything back together correctly.
Because this repair involves gas connections and combustion components, safety is especially important. The gas supply must be shut off before beginning, and all gas connections must be checked for leaks before relighting the water heater. Always follow the manufacturer’s instructions for your specific model.
Watch the full video below for the complete step-by-step demonstration and see how to replace a thermopile on this type of gas water heater.
Frequently Asked Questions
What does a thermopile do on a gas water heater?
A thermopile generates a small amount of electrical voltage from the pilot flame. That voltage helps keep the gas control valve open so the water heater can operate.
Can a bad thermopile cause a pilot light to go out?
Yes. A failing thermopile may not generate enough voltage to keep the gas control valve operating, causing the pilot light to go out or fail to stay lit.
Can you replace just the thermopile instead of the entire burner assembly?
On some water heaters, yes. The thermopile is a replaceable component of the pilot assembly, although the exact design varies by manufacturer and model.
Are water heater thermopiles universal?
No. Replacement thermopiles and pilot assemblies can vary depending on the water heater manufacturer and model. Always verify compatibility before purchasing replacement parts.