What a Flame Sensor Is and Why It Matters

February 26, 2017

Receiving your routine furnace maintenance helps keep your furnace working up to 30 percent more efficient and helps extend the life of your furnace. But things can still stop working, and when they do, you might feel like there is always something else.

This time it’s your motor, next time it’s your control board. 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 sequence, your gas furnace enters a process where either a hot surface ignitor or a spark actually ignites the gas. Once the gas is ignited, the flame sensor creates a current of electricity. The current is quantified in micro amps. If the furnace’s control board fails to read the right level of micro amps, the furnace will stop giving the system fuel to stop an explosion.

Over time, if the flame sensor is not adequately cleaned, oxidation or carbon buildup can hinder the flame sensor’s ability to operate properly, which can cause the furnace to malfunction.

The way to diagnose if an unclean flame sensor is the reason for 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 culprit, the furnace expert will clean the sensor with steel wool. If dirt was the single factor, we will see a notably higher amp reading. If the reading doesn’t change, the technician will carry on with the heating system repair diagnostic process.

If you aren’t certain your heating system is going to make it through these last few weeks of winter, give Teays Valley 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 furnace.

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