What a Flame Sensor Is and Why It Matters

Receiving your routine furnace maintenance helps keep your heating system operating up to 30 percent more efficient and helps extend the life of your system. But things could still go wrong, 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.

What is a flame sensor, anyway?

A flame sensor is an important safety feature on your gas heating system. During the ignition pattern, your gas furnace undergoes a process where a spark or a hot surface ignitor actually ignites the gas. Once the gas is ignited, the flame sensor produces a current of electricity. The electricity is calculated in micro amps. If the furnace’s control board doesn’t read the right level of micro amps, the furnace will no longer give the system fuel to stop 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 work properly, which can cause the furnace to malfunction.

The way to determine if a soiled 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 offender, the heating expert will clean the sensor with steel wool. If dirt was the only factor, we will see a significantly higher amp reading. If the reading shows no change, the technician will proceed with the heating equipment repair diagnostic process.

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