Gas Furnace Components

With temperatures dropping to the 50s at night now, you may be thinking about turning on your furnace in the near future. Knowing the key components of your gas furnace may help you troubleshoot where your system may be malfunctioning if you do run into any furnace problems this coming season.

Igniter and Pilot Light

Older furnaces will have a pilot light that burns constantly to light the gas when the gas valve is open. More modern furnaces use a hot surface igniter that will glow red hot and ignite the gas.


A thermocouple is used with a pilot light to detect whether the pilot light is lit. If it doesn’t detect heat from the pilot light, it will shut the gas off.

Flame Sensor

A flame sensor works as a safety device to detect heat when a hot surface igniter is used. If it doesn’t detect heat it will shut off the gas.

Gas valve

The gas valve opens and closes automatically when it gets a call from the thermostat for heat or when the set temperature is reached. When the gas valve is open, it allows gas to flow to the burner where it is combusted.

Heat Exchanger

Heat exchangers are long metal tubes that are S-shaped. Flames burn inside the tubes and toxic gases such as carbon monoxide are vented out of your home from there.

Indoor Blower Motor

The blower moves air over the heat exchanger which warms up the air and gets cycled through your duct work and into your vents.

If you’re ever in a situation where your furnace doesn’t seem to be functioning properly, you should always call a professional technician to assess your situation. Call us at 785-341-4193 and we’ll be there 24/7 for all of your furnace needs!

De Hart Plumbing Heating and Cooling, serving Manhattan Kansas, Junction City Kansas, Wamego Kansas, Topeka Kansas, and some surrounding areas.

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