What a Flame Sensor Is and Why It Matters

February 26, 2017

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

This time it’s your motor, next time it’s your control board. Now you have to have your flame sensor replaced.

Also, what is a flame sensor?

A flame sensor is a crucial safety component on your gas heating equipment. During the ignition pattern, your gas furnace goes through a process where either a spark or a hot surface igniter will ignite the gas. When the gas is ignited, the flame sensor produces a current of electricity. The electricity is quantified in micro amps. If the furnace’s control board doesn’t read the proper level of micro amps, the furnace will stop giving the system fuel to avoid an explosion.

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

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

If you aren’t certain your furnace is going to outlast these last few weeks of winter, give TML 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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