What a Flame Sensor Is and Why It Matters

Receiving your seasonal furnace maintenance helps keep your heating equipment working up to thirty percent more efficient and helps extend the life of the equipment. But things could still stop working, and when they do, you could feel like there is always something else.

This time it’s your blower, next time it’s your control valve. Now you need to replace your flame sensor.

What is a flame sensor, anyway?

A flame sensor is a crucial safety component on your gas heating equipment. During the ignition pattern, your gas furnace undergoes a process where either a spark or a hot surface igniter will actually ignite the gas. As the gas is ignited, the flame sensor generates a current of electricity. This is quantified 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 stop an explosion.

Over time, if the flame sensor is not cleaned properly, oxidation or carbon buildup can interfere with the flame sensor’s ability to work properly, which can end up causing the heating system to malfunction.

The way to determine if a soiled flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert furnace technician can supply you. If a dirty flame sensor is the culprit, the furnace 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 shows no change, the technician will continue with the furnace repair diagnostic process.

If you aren’t certain your furnace is going to make it through these last few weeks of winter, give Air Engineers Service Experts a call and we’ll come out and provide you with a full furnace maintenance or a free in-home estimate on a new furnace.

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