What a Flame Sensor Is and Why It Matters

Scheduling your seasonal furnace maintenance helps keep your furnace operating up to thirty percent more efficient and helps extend the life of your system. But things can still malfunction, and when they do, you may feel like there is always something else.

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

Also, what is a flame sensor?

A flame sensor is a critical safety element on your gas furnace. During the ignition pattern, your gas furnace enters a process where either a spark or a hot surface igniter will actually ignite the gas. As the gas is ignited, the flame sensor produces a current of electricity. The current is quantified in micro amps. If the furnace’s control board does not read the proper level of micro amps, the furnace will stop giving the system fuel to stop an explosion.

Over time, if the flame sensor is not cleaned appropriately, 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 the reason for a furnace malfunction is to take a micro amp draw reading, which a professional furnace technician can supply 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 significantly higher amp reading. If the reading does not change, the technician will continue with the heating equipment repair diagnostic process.

If you aren’t certain your heating system is going to make it through these last few weeks of winter, give Jack Nelson Service Experts 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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