What a Flame Sensor Is and Why It Matters

Scheduling your routine furnace maintenance helps keep your heating system running up to 30 percent more efficient and helps extend the life of your furnace. But things may still malfunction, and when they do, you might feel like there is always something else.

This time it’s your heat exchanger, next time it’s your control board. Now your find out the flame sensor has to be replaced.

Also, what is a flame sensor?

A flame sensor is a crucial safety element on your gas furnace. During the ignition sequence, your gas furnace enters a process where either a spark or a hot surface igniter will actually ignite the gas. Once the gas is ignited, the flame sensor produces a current of electricity. The electricity is measured in micro amps. If the furnace’s control board doesn’t read the right level of micro amps, the furnace will stop giving the system fuel to prevent an explosion.

Over time, if the flame sensor is not cleaned properly, oxidation or carbon buildup can impede the flame sensor’s ability to work properly, which can result in a malfunction of the furnace.

The way to establish if an unclean flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert furnace technician can provide you. If a dirty flame sensor is the reason, the heating expert will clean the sensor with steel wool. If dirt was the single factor, we will see a much higher amp reading. If the reading doesn’t change, the technician will proceed with the furnace repair diagnostic process.

If you aren’t sure your furnace is going to survivie these last few weeks of winter, give Service Experts Heating & Air Conditioning a call and we’ll come out and give you a full furnace maintenance or a complimentary in-home estimate on a new furnace.

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