What a Flame Sensor Is and Why It Matters

Scheduling your routine furnace maintenance helps keep your heating system working up to thirty percent more efficient and helps extend the life of your furnace. But things could still malfunction, 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 pressure switch. Now you need to replace your flame sensor.

Also, what is a flame sensor?

A flame sensor is a crucial safety feature on your gas heating equipment. During the ignition sequence, your gas furnace undergoes a process where either a hot surface ignitor or a spark will ignite the gas. Once the gas is ignited, the flame sensor creates a current of electricity. The electricity is calculated 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 prevent an explosion.

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

The way to establish if a soiled 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 culprit, the heating expert will clean the sensor with steel wool. If dirt was the only factor, we will see a notably higher amp reading. If the reading doesn’t change, the technician will carry on with the furnace repair diagnostic process.

If you aren’t certain your heating system is going to survivie these last few weeks of winter, give Service Experts Heating & Air Conditioning a call and we’ll come out and provide you with a full furnace maintenance or a free in-home estimate on a new HVAC system.

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