What a Flame Sensor Is and Why It Matters

Receiving your annual furnace maintenance helps keep your heating system working up to 30% more efficient and helps extend the life of your furnace. But things can still malfunction, and when they do, you might 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 a crucial safety component on your gas heating equipment. During the ignition pattern, your gas furnace undergoes a process where either a hot surface ignitor or a spark 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 no longer give 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 cause the furnace to malfunction.

The way to diagnose 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 guilty party, the technician will clean the sensor with steel wool. If dirt was the sole factor, we will see a significantly 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 give you a full furnace maintenance or a complimentary in-home estimate on a new heating system.

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