Coronavirus Update: We care about your health and continue to service our customers safely. Read More

Skip navigation

Serving The Greater Riverside Area For 60+ Years


A-Avis Home Services Plumbing, Heating & Air Conditioning, Inc. Blog

Why Won’t My Furnace Stay Lit?

There are few worse feelings than trying to turn on your heat during a cold day and getting nothing. Furnaces are combustion heaters, and rely on a few different parts to stay lit. If your furnace doesn’t turn on or stay lit, chances are it is because one or more of these key parts is malfunctioning. Let’s examine the various factors that can contribute to your furnace refusing to stay lit.

Bad Thermocouple

Chances are good that if you’re using a natural gas furnace, you’ve got a pilot light to serve as the ignition source. The pilot light is a small, constantly burning flame at the bottom of your furnace that is used to light the main burners and turn the furnace on. If the pilot light goes out, your furnace will not be able to light itself.

The thermocouple is a heat sensor that is installed next to the pilot light, and controls the gas valve that provides the fuel to keep the flame burning. When the pilot light goes out, the thermocouple closes the gas valve to keep the gas from filling the house. If the thermocouple is malfunctioning, it often loses the ability to sense the heat from the pilot light. This causes it to close the gas valve while the pilot light is still on, smothering it and preventing the furnace from working. If your furnace isn’t staying lit, check your pilot light. If your pilot light won’t stay lit, there is a good chance that you have a bad thermocouple.

Burner Malfunction

The burners are the source of heat output for your furnace. If your burners aren’t working properly, your furnace will have no way to generate heat. Problems with the burners are less common than with the pilot light, but they do happen. Often, the burners on your furnace will become dirty and caked with carbon. This can hinder one or more burners from operating at peak efficiency. A blockage in the gas line is also possible, which can starve out the burners and prevent them from igniting at all.

If your furnace is refusing to stay lit, call Avis Plumbing, Heating and Air. We provide heating repairs throughout the Riverside area.

Comments are closed.