What a Flame Sensor Is and Why It Matters

February 26, 2017

Receiving your seasonal furnace maintenance helps keep your heating system operating up to 30% more efficient and helps extend the life of the equipment. But things could still stop working, and when they do, you may feel like there is always something else.

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

By the way – what is a flame sensor?

A flame sensor is a crucial safety element 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 creates a current of electricity. The current is calculated in micro amps. If the furnace’s control board doesn’t read the correct 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 cleaned properly, oxidation or carbon buildup can restrict the flame sensor’s ability to operate properly, which can end up causing the heating system to malfunction.

The way to establish if a dirty 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 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 furnace is going to survivie these last few weeks of winter, give Komfort Air 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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