Pilot Light went out on Furnace

Pilot Light went out on Furnace Heating and Cooling

The pilot light went out in your home furnace and you aren’t sure what to do.  First,  here is some background info. The pilot light on your furnace is a small flame that hits a thermocouple above it, which creates an electrical current that holds a pilot valve open, allowing the pilot gas to flow.  If the thermocouple gets too cool, then the gas intake will shut off and flame will die.  So when the pilot light goes out on your furnace, you can usually pin it down to one of three causes:

Lazy Flame

A lazy flame is usually yellow in color and weak when compared to the blue, noisy, crisp pilot flames.

Without the proper amount of oxygen, the blue flame will turn into a weak yellow flame and no longer heat up the solenoid properly, leading it to extinguish the solenoid.  Check your air intake valves by the pilot light; they often times gets clogged with dirt and make the pilot flame weak and ineffective.  Strengthen the flame by sanding and clearing off the grime obstructing the intake valves.

Bad Thermocouple

Since the thermocouple regulates the amount of pilot gas released, the thermocouple itself is an integral part of the pilot light.  If the thermocouple is bad or faulty, then it will not properly register the heat given off by the pilot flame and erroneously extinguish the flame.  In some cases, you may be able to sand down the thermocouple (there may be dirt or grime that makes the temperature readings inaccurate), but in other cases, you may need to replace the thermocouple itself.  Fortunately, the thermocouple is a relatively cheap replacement part you can find around your local hardware stores (usually around $10).


Another potential reason that the pilot light goes out is a backdraft from your vents.  High winds may create a backdraft in your vents, blowing wind back toward you pilot light and extinguishing it.  While this is uncommon, you may want to have a professional look at your situation to be certain that you don’t need to completely replace your furnace.  TalkLocal can connect you with high quality heating experts in your area in just minutes! It’s fast, easy, and completely free!

One Response to “Pilot Light went out on Furnace”

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