What a Flame Sensor Is and Why It Matters

Setting up your routine furnace maintenance helps keep your heating equipment operating up to 30 percent more efficient and helps extend the life of the equipment. But things could still stop working, 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.

What is a flame sensor, anyway?

A flame sensor is an important safety component on your gas heating system. During the ignition pattern, your gas furnace goes through a process where either a hot surface ignitor or a spark will actually ignite the gas. As 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 fails to read the correct level of micro amps, the furnace will no longer give the system fuel to prevent an explosion.

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

The way to determine if an unclean flame sensor is causing a furnace malfunction is to take a micro amp draw reading, which an expert furnace technician can give you. If a dirty flame sensor is the guilty party, the furnace expert will clean the sensor with steel wool. If dirt was the only factor, we will see a much higher amp reading. If the reading shows no change, the technician will carry on with the heating equipment repair diagnostic process.

If you aren’t confident your furnace is going to outlast 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 furnace.

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