What a Flame Sensor Is and Why It Matters

Receiving your annual furnace maintenance helps keep your heating equipment operating up to 30% more efficient and helps extend the life of the equipment. But things could still malfunction, and when they do, you may feel like it’s always something else.

This time it’s your motor, 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 furnace. During the ignition pattern, your gas furnace undergoes a process where either a hot surface ignitor or a spark actually ignites the gas. When the gas is ignited, the flame sensor generates a current of electricity. This is calculated in micro amps. If the furnace’s control board fails to read the correct 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 appropriately, oxidation or carbon buildup can impede the flame sensor’s ability to work properly, which can result in a malfunction of the furnace.

The way to diagnose if an unclean flame sensor is to blame for a furnace malfunction is to take a micro amp draw reading, which an expert furnace technician can give you. If a dirty flame sensor is the culprit, the technician will clean the sensor with steel wool. If dirt was the sole factor, we will see a notably higher amp reading. If the reading doesn’t change, the technician will proceed with the heating equipment repair diagnostic process.

If you aren’t sure your furnace is going to make it through these last few weeks of winter, give Robinson Service Experts a call and we’ll come out and provide you with a full furnace maintenance or a no-charge in-home estimate on a new HVAC system.