Why Pilot Light Keeps Going Out on Gas Furnace: Two Possible Reasons

There are several reasons why the pilot light keeps going out on the gas furnace. Usually, you can find a pilot light on an older model of propane appliances. Basically, pilot light is a small flame that is lit all the time. The flame is located inside the appliance.

There are two functions of a pilot light. First, it is to restart an appliance’s main burner. Second, to make sure there are no gas leaks.

Basically, two sources can cause gas furnace pilot light to go out occasionally: the thermocouple and the pilot light.

Problematic Thermocouple

If a gas fireplace pilot light goes out, problems with the thermocouple might be the cause. A thermocouple is a component of a gas furnace that you can find near the pilot light.

The thermocouple is meant to stop the gas if the electric igniter fails or if the pilot light goes out. The thermocouple is supposed to shut the gas valve so the gas will not get into your home, which, when it is ignited, can cause an explosion.

Problems in the thermocouple might be the reason why the pilot light keeps going out on a gas furnace. Some problems can make the gas fireplace pilot light goes out. If the thermocouple on your gas furnace is broken, then it will close the valve regardless the pilot light is working or not.

In this case, then you will be unable to open the valve by yourself. If this happens to you, what you need to do is ask for a professional HVAC contractor to change your thermocouple. Thankfully, the cost for this is relatively inexpensive.

Why Pilot Light Keeps Going Out On Gas Furnace

Why Pilot Light Keeps Going Out on Gas Furnace

A gas fireplace pilot light goes out because there is a buildup of soot in the thermocouple. As you use your gas furnace, naturally, soot will build up. If you do not clean it, it can cause a problem with the thermocouple. A soot buildup makes the thermocouple can’t work properly since it blocks the flame. Thankfully, it is much easier to solve this problem than a broken thermocouple. The only thing you need to do is to clean the soot off. You can do this with a wire brush.

Last but not least, the gas fireplace pilot’s reason is that the thermocouple is not enveloped by the pilot light flame. The thermocouple can tell when the flame is on when the top of it is enveloped by the pilot light flame. So, when it is not, it can make the pilot light goes out.

If your furnace pilot light keeps going out after replacing the thermocouple, then maybe there is another damage you must check.

Problem with Pilot Light

If there is a problem with your pilot light, it can also cause the pilot light to go out. If the flame is blue, then there is nothing wrong with the pilot light. But if it is yellow, it means the flame is not hot enough to reach the thermocouple. Usually, the yellow flame is caused by a lack of air caused by the accumulation of dirt that gets in from the light opening.

Basically, there are two possible reasons why the pilot light keeps going out on the gas furnace: the thermocouple of the pilot light itself.

Thanks to reading this article about what would cause a pilot light to go out on a furnace.

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John Burns is an experienced author and expert home improvement advice. With years of practical experience in the field authored several informative articles on various aspects related to home improvement, including installation, maintenance, and repair.