What a Flame Sensor Is and Why It Matters

February 26, 2017

Setting up your seasonal furnace maintenance helps keep your heating system operating up to 30 percent more efficient and helps extend the life of the equipment. But things may still go wrong, 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 need to replace your flame sensor.

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 spark or a hot surface igniter will actually ignite the gas. Once the gas is ignited, the flame sensor generates a current of electricity. The current is quantified in micro amps. If the furnace’s control board fails to read the correct level of micro amps, the furnace will quit 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 end up causing the heating system to malfunction.

The way to establish if an unclean flame sensor is to blame for a furnace malfunction is to take a micro amp draw reading, which an expert furnace technician can provide you. If a dirty flame sensor is the offender, the technician will clean the sensor with steel wool. If dirt was the single factor, we will see a much higher amp reading. If the reading doesn’t change, the technician will proceed with the heating equipment repair diagnostic process.

If you aren’t sure your heating equipment is going to make it through these last few weeks of winter, give Bob Brown Service Experts a call and we’ll come out and give you a full furnace maintenance or a no-charge in-home estimate on a new heating system.

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