What a Flame Sensor Is and Why It Matters

Scheduling your routine 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 malfunction, and when they do, you could feel like you’re always hearing about something else.

This time it’s your heat exchanger, next time it’s your control valve. Now your find out the flame sensor has to be 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 enters a process where either a hot surface ignitor or a spark will actually ignite the gas. As the gas is ignited, the flame sensor produces a current of electricity. The electricity is quantified in micro amps. If the furnace’s control board does not read the right level of micro amps, the furnace will no longer give the system fuel to avoid an explosion.

Over time, if the flame sensor is not adequately cleaned, 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 a soiled flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert heating technician can supply you. If a dirty flame sensor is the guilty party, the heating expert will clean the sensor with steel wool. If dirt was the single factor, we will see a significantly higher amp reading. If the reading shows no change, the technician will continue with the heating system repair diagnostic process.

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