What a Flame Sensor Is and Why It Matters

February 26, 2017

Receiving your routine furnace maintenance helps keep your heating equipment running up to thirty percent more efficient and helps extend the life of your furnace. But things can still go wrong, 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 valve. Now you have to have your flame sensor replaced.

By the way – what is a flame sensor?

A flame sensor is a critical safety component on your gas heating equipment. During the ignition pattern, your gas furnace goes through a process where a spark or a hot surface ignitor will ignite the gas. As the gas is ignited, the flame sensor generates a current of electricity. This 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 stop an explosion.

Over time, if the flame sensor is not adequately cleaned, 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 establish if a soiled flame sensor is the reason 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 guilty party, the heating expert will clean the sensor with steel wool. If dirt was the only factor, we will see a much higher amp reading. If the reading shows no change, the technician will continue with the heating equipment repair diagnostic process.

If you aren’t certain your furnace is going to make it through these last few weeks of winter, give Midway Services a call and we’ll come out and perform a full furnace maintenance or a no-charge in-home estimate on a new heating system.

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