What a Flame Sensor Is and Why It Matters

February 26, 2017

Receiving your annual furnace maintenance helps keep your heating system working up to thirty percent more efficient and helps extend the life of the equipment. But things may still stop working, and when they do, you could feel like there is always something else.

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

What is a flame sensor, anyway?

A flame sensor is a critical safety component on your gas heating system. During the ignition pattern, your gas furnace goes through a process where either a spark or a hot surface igniter actually ignites the gas. When 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 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 restrict the flame sensor’s ability to work properly, which can end up causing the heating system to malfunction.

The way to determine if a dirty 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 offender, 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 doesn’t change, the technician will carry on with the heating equipment repair diagnostic process.

If you aren’t confident your heating system is going to outlast these last few weeks of winter, give Winnipeg Supply Service Experts a call and we’ll come out and perform a full furnace maintenance or a no-charge in-home estimate on a new HVAC system.

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