What a Flame Sensor Is and Why It Matters

February 26, 2017

Setting up your routine furnace maintenance helps keep your heating equipment working up to 30% more efficient and helps extend the life of your system. But things could still go wrong, 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 need to replace your flame sensor.

By the way – what is a flame sensor?

A flame sensor is a crucial safety component on your gas heating equipment. During the ignition cycle, your gas furnace undergoes a process where either a hot surface ignitor or a spark actually ignites the gas. As the gas is ignited, the flame sensor produces a current of electricity. This is quantified in micro amps. If the furnace’s control board does not read the proper level of micro amps, the furnace will quit giving 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 function properly, which can result in a malfunction of the furnace.

The way to determine if an unclean flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which a professional furnace technician can provide you. If a dirty flame sensor is the guilty party, the technician will clean the sensor with steel wool. If dirt was the single factor, we will see a notably higher amp reading. If the reading shows no change, the technician will continue with the heating equipment repair diagnostic process.

If you aren’t sure your furnace is going to outlast these last few weeks of winter, give A1 Chesney Service Experts Heating & Air Conditioning a call and we’ll come out and provide you with a full furnace maintenance or a complimentary in-home estimate on a new heating system.

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