What a Flame Sensor Is and Why It Matters

Scheduling your seasonal furnace maintenance helps keep your furnace running up to 30 percent more efficient and helps extend the life of your furnace. But things can still go wrong, and when they do, you could feel like it’s always something else.

This time it’s your heat exchanger, next time it’s your control valve. Now you have to have your flame sensor replaced.

Also, what is a flame sensor?

A flame sensor is an important safety component on your gas heating system. During the ignition sequence, your gas furnace undergoes a process where a spark or a hot surface ignitor will actually ignite the gas. Once the gas is ignited, the flame sensor generates a current of electricity. The electricity is calculated in micro amps. If the furnace’s control board fails to read the right level of micro amps, the furnace will quit giving the system fuel to prevent an explosion.

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

The way to diagnose if a soiled flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert heating technician can give you. If a dirty flame sensor is the guilty party, the furnace expert will clean the sensor with steel wool. If dirt was the sole factor, we will see a notably higher amp reading. If the reading shows no change, the technician will proceed with the heating equipment repair diagnostic process.

If you aren’t confident your heating equipment is going to outlast these last few weeks of winter, give Stark Services a call and we’ll come out and give you a full furnace maintenance or a free in-home estimate on a new furnace.

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