What a Flame Sensor Is and Why It Matters

Setting up your annual furnace maintenance helps keep your heating system running up to thirty percent more efficient and helps extend the life of the equipment. But things could still malfunction, 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 your find out the flame sensor has to be replaced.

By the way – what is a flame sensor?

A flame sensor is a critical safety component on your gas furnace. During the ignition pattern, your gas furnace enters a process where either a hot surface ignitor or a spark will actually ignite the gas. As the gas is ignited, the flame sensor produces a current of electricity. This is quantified in micro amps. If the furnace’s control board doesn’t read the proper level of micro amps, the furnace will no longer give the system fuel to prevent an explosion.

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

The way to determine if a dirty flame sensor is the reason for a furnace malfunction is to take a micro amp draw reading, which a professional furnace technician can supply you. If a dirty flame sensor is the guilty party, the technician will clean the sensor with steel wool. If dirt was the single factor, we will see a significantly higher amp reading. If the reading doesn’t change, the technician will continue with the furnace repair diagnostic process.

If you aren’t confident your furnace is going to make it through these last few weeks of winter, give Rolf Griffin Service Experts a call and we’ll come out and perform a full furnace maintenance or a free in-home estimate on a new heating system.

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