What a Flame Sensor Is and Why It Matters

February 26, 2017

Setting up your routine furnace maintenance helps keep your heating equipment working up to thirty percent more efficient and helps extend the life of your system. But things may still malfunction, and when they do, you could feel like you’re always hearing about something else.

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

By the way – what is a flame sensor?

A flame sensor is a crucial safety element on your gas heating system. During the ignition pattern, your gas furnace enters a process where a spark or a hot surface ignitor actually ignites the gas. Once the gas is ignited, the flame sensor generates a current of electricity. This is quantified in micro amps. If the furnace’s control board does not 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 adequately cleaned, oxidation or carbon buildup can impede the flame sensor’s ability to work properly, which can cause the furnace to malfunction.

The way to diagnose if an unclean flame sensor is causing 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 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 proceed with the furnace repair diagnostic process.

If you aren’t certain your heating equipment is going to outlast these last few weeks of winter, give D.A. Bennett Service Experts Heating & Air Conditioning 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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