What a Flame Sensor Is and Why It Matters

Receiving your annual furnace maintenance helps keep your furnace operating up to thirty percent more efficient and helps extend the life of your system. But things may still go wrong, and when they do, you may feel like it’s always something else. 

This time it’s your heat exchanger, next time it’s your control valve. Now you have to have your flame sensor replaced. 

Also, what is a flame sensor? 

A flame sensor is a crucial safety element on your gas furnace. During the ignition cycle, your gas furnace goes through a process where either a hot surface ignitor or a spark will ignite the gas. Once the gas is ignited, the flame sensor produces a current of electricity. The current is calculated in micro amps. If the furnace’s control board doesn’t read the proper level of micro amps, the furnace will quit giving the system fuel to avoid an explosion. 

Over time, if the flame sensor is not cleaned properly, oxidation or carbon buildup can hinder the flame sensor’s ability to operate properly, which can result in a malfunction of the furnace. 

The way to establish if a dirty flame sensor is to blame for 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 reason, the technician will clean the sensor with steel wool. If dirt was the only factor, we will see a much higher amp reading. If the reading doesn’t change, the technician will carry on with the heating system repair diagnostic process. 

If you aren’t confident your heating equipment is going to survivie these last few weeks of winter, give Service Experts Heating & Air Conditioning 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.