What a Flame Sensor Is and Why It Matters

Receiving 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 can still stop working, and when they do, you could feel like it’s always something else.

This time it’s your blower, next time it’s your control board. Now you have to have your flame sensor replaced.

Also, what is a flame sensor?

A flame sensor is an important safety feature on your gas heating system. During the ignition sequence, your gas furnace goes through a process where either a spark or a hot surface igniter actually ignites the gas. Once the gas is ignited, the flame sensor produces a current of electricity. This is calculated in micro amps. If the furnace’s control board fails to read the right level of micro amps, the furnace will quit giving the system fuel to prevent an explosion.

Over time, if the flame sensor is not cleaned appropriately, oxidation or carbon buildup can interfere with the flame sensor’s ability to operate properly, which can end up causing the heating system to malfunction.

The way to diagnose if a soiled 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 offender, 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 does not change, the technician will proceed with the furnace repair diagnostic process.

If you aren’t certain your heating equipment is going to outlast these last few weeks of winter, give Sunbeam Service Experts a call and we’ll come out and perform a full furnace maintenance or a complimentary in-home estimate on a new HVAC system.

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