What a Flame Sensor Is and Why It Matters

February 26, 2017

Scheduling your routine furnace maintenance helps keep your heating equipment running 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 could feel like there is always something else.

This time it’s your blower, next time it’s your control valve. Now your find out the flame sensor has to be replaced.

What is a flame sensor, anyway?

A flame sensor is a critical safety element on your gas furnace. During the ignition pattern, your gas furnace undergoes a process where either a spark or a hot surface igniter will ignite the gas. When 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 right 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 appropriately, oxidation or carbon buildup can impede the flame sensor’s ability to work properly, which can cause the furnace to malfunction.

The way to establish 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 culprit, the furnace expert will clean the sensor with steel wool. If dirt was the single factor, we will see a notably higher amp reading. If the reading does not change, the technician will continue with the furnace repair diagnostic process.

If you aren’t sure your furnace is going to make it through these last few weeks of winter, give Falso 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 heating system.

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