What a Flame Sensor Is and Why It Matters

February 26, 2017

Scheduling your routine furnace maintenance helps keep your furnace running up to 30 percent more efficient and helps extend the life of the equipment. But things may still malfunction, and when they do, you may feel like there is always something else.

This time it’s your motor, 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 an important safety element on your gas heating system. During the ignition cycle, your gas furnace enters a process where either a hot surface ignitor or a spark actually ignites the gas. When the gas is ignited, the flame sensor produces a current of electricity. The electricity 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 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 establish if a dirty flame sensor is to blame 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 heating expert will clean the sensor with steel wool. If dirt was the single factor, we will see a much higher amp reading. If the reading does not change, the technician will continue with the heating system repair diagnostic process.

If you aren’t confident your heating system is going to make it through 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 heating system.

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