What a Flame Sensor Is and Why It Matters

Scheduling your routine furnace maintenance helps keep your heating system operating up to 30% more efficient and helps extend the life of your system. But things can still stop working, and when they do, you may feel like there is always something else.

This time it’s your motor, next time it’s your control valve. Now you need to replace your flame sensor.

Also, what is a flame sensor?

A flame sensor is an important safety component on your gas heating equipment. During the ignition cycle, your gas furnace goes through a process where a spark or a hot surface ignitor actually ignites the gas. As the gas is ignited, the flame sensor produces a current of electricity. This is measured in micro amps. If the furnace’s control board does not read the proper 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 properly, oxidation or carbon buildup can hinder the flame sensor’s ability to function properly, which can result in a malfunction of the furnace.

The way to establish if an unclean flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert heating technician can provide you. If a dirty flame sensor is the guilty party, the heating expert will clean the sensor with steel wool. If dirt was the sole factor, we will see a notably higher amp reading. If the reading does not change, the technician will proceed with the heating equipment repair diagnostic process.

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