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Why Aren’t the Burners Lighting in My Gas Furnace?

Your gas furnace contains a few key components that must all work together in order to keep your home warm and cozy. Furnaces burn fuel—either natural gas or propane—in order to create heat. Heat generates in a combustion chamber, but this process also produces by-products like water vapor and carbon monoxide which must then vent through a flue or vent pipe. Hot gasses travel through the heat exchanger, and as a blower fan pushes air over the heat exchanger, the air warms up before it moves through the ducts and into your home.

If the burners won’t light up, it’s because natural gas has not been delivered to the burner for some reason or because safety measures won’t allow the burner to become lit. If the ignition process fails, it may be due to the thermocouple or flame sensor, two components with similar functions used in a standing gas pilot or intermittent or hot surface ignition pilot furnace. It could also point to a few other problems as well, so you should always trust heating repair to a trained technician who knows the proper safety procedures and can quickly identify the issue.

Talk to a professional technician about your heating in Salt Lake City by calling At Your Service Plumbing, Heating & Air.

  • Broken Thermocouple: A thermocouple is a component used in a standing pilot furnace, a model in which the pilot continuously stays lit. The thermocouple is part of the ignition assembly in the furnace, and its purpose is to sense whether it is safe to ignite the gas and send fuel to the burner. This is primarily a safety feature to keep the gas valve closed in case the pilot light goes out. If this component is broken, the gas valve should still remain closed. However, it will need replacement in order to light the burners.
  • Dirty Flame Sensor: Modern furnaces actually use a flame sensor instead of a thermocouple because modern furnaces most often use hot surface ignition to ignite the burners. This eliminates the need for a pilot light, as the flame sensor simply detects when gas has been ignited and shuts off the igniter afterwards. This part is hindered by any dust, and may need an expert to safely clean it from time to time, perhaps during annual heating maintenance.

Call At Your Service Plumbing, Heating & Air today to  talk to an expert and learn more about what may go wrong with your heating system or schedule heating repairs in Salt Lake City.

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