What a Flame Sensor Is and Why It Matters

Receiving your routine furnace maintenance helps keep your heating system working up to thirty percent more efficient and helps extend the life of your system. But things can still stop working, and when they do, you could feel like it’s always something else.

This time it’s your heat exchanger, next time it’s your control board. Now your find out the flame sensor has to be replaced.

Also, what is a flame sensor?

A flame sensor is a critical safety feature on your gas heating equipment. During the ignition pattern, your gas furnace undergoes a process where either a hot surface ignitor or a spark actually ignites the gas. Once the gas is ignited, the flame sensor produces a current of electricity. This is calculated 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 avoid an explosion.

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

The way to determine if an unclean flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which a professional furnace technician can give you. If a dirty flame sensor is the reason, the furnace expert will clean the sensor with steel wool. If dirt was the sole factor, we will see a much higher amp reading. If the reading does not change, the technician will proceed with the furnace repair diagnostic process.

If you aren’t sure your furnace is going to outlast these last few weeks of winter, give Service Experts Heating & Air Conditioning 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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