What a Flame Sensor Is and Why It Matters

February 26, 2017

Receiving your routine furnace maintenance helps keep your furnace running up to 30% more efficient and helps extend the life of your system. But things can still stop working, and when they do, you might feel like there is always something else.

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

Also, what is a flame sensor?

A flame sensor is an important safety component on your gas heating equipment. During the ignition sequence, your gas furnace undergoes a process where a spark or a hot surface ignitor will actually ignite the gas. As the gas is ignited, the flame sensor produces a current of electricity. The current is calculated in micro amps. If the furnace’s control board does not read the proper level of micro amps, the furnace will stop giving the system fuel to stop an explosion.

Over time, if the flame sensor is not cleaned properly, oxidation or carbon buildup can restrict the flame sensor’s ability to work properly, which can cause the furnace to malfunction.

The way to establish if an unclean flame sensor is to blame for a furnace malfunction is to take a micro amp draw reading, which an expert heating 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 only factor, we will see a notably higher amp reading. If the reading does not change, the technician will proceed with the heating equipment repair diagnostic process.

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

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