What a Flame Sensor Is and Why It Matters

February 26, 2017

Scheduling your seasonal furnace maintenance helps keep your furnace operating up to 30 percent more efficient and helps extend the life of your furnace. But things can still go wrong, and when they do, you could 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 component on your gas heating system. During the ignition sequence, your gas furnace goes through a process where a spark or a hot surface ignitor actually ignites the gas. When the gas is ignited, the flame sensor creates a current of electricity. The electricity is measured in micro amps. If the furnace’s control board does not read the correct 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 restrict the flame sensor’s ability to work properly, which can result in a malfunction of the furnace.

The way to diagnose if a soiled flame sensor is causing 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 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 shows no change, the technician will proceed with the heating equipment repair diagnostic process.

If you aren’t sure your heating equipment is going to outlast these last few weeks of winter, give Stark Services a call and we’ll come out and give you a full furnace maintenance or a free in-home estimate on a new heating system.

Contact Us