What a Flame Sensor Is and Why It Matters

February 26, 2017

Setting up your seasonal furnace maintenance helps keep your heating system running up to 30% more efficient and helps extend the life of your furnace. But things may still go wrong, 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 control board. Now your find out the flame sensor has to be replaced.

Also, what is a flame sensor?

A flame sensor is a crucial safety feature on your gas heating equipment. During the ignition cycle, your gas furnace undergoes a process where a spark or a hot surface ignitor will 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 doesn’t read the right level of micro amps, the furnace will quit giving the system fuel to stop 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 operate properly, which can result in a malfunction of the furnace.

The way to diagnose if a soiled flame sensor is the reason for a furnace malfunction is to take a micro amp draw reading, which an expert heating technician can give you. If a dirty flame sensor is the guilty party, the heating expert will clean the sensor with steel wool. If dirt was the sole factor, we will see a notably higher amp reading. If the reading shows no change, the technician will proceed with the heating system repair diagnostic process.

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

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