What a Flame Sensor Is and Why It Matters

Scheduling your routine furnace maintenance helps keep your furnace running up to 30 percent more efficient and helps extend the life of the equipment. But things could still go wrong, and when they do, you may feel like there is always something else.

This time it’s your blower, next time it’s your pressure switch. Now your find out the flame sensor has to be replaced.

Also, what is a flame sensor?

A flame sensor is a critical safety feature on your gas heating system. During the ignition cycle, your gas furnace undergoes a process where a spark or a hot surface ignitor will ignite the gas. When the gas is ignited, the flame sensor creates a current of electricity. This is measured in micro amps. If the furnace’s control board fails to read the proper level of micro amps, the furnace will stop giving the system fuel to avoid an explosion.

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

The way to determine if a soiled flame sensor is to blame 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 reason, the furnace expert 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 system repair diagnostic process.

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

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