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What You Should Know About A Dirty Flame Sensor

What Is Flame Sensor?

In a gas furnace system, the flame sensor is the most important component when it comes to safety. When a furnace is activated, gas is ignited by a spark or hot surface and then an electrical current is produced by the flame sensor. The electricity is calibrated in microamps which are monitored by the control board inside the furnace. If improper microamps are detected, then the furnace shuts down to avoid an explosion. It’s important to keep the flame sensor clean so that the entire system continues to run smoothly and the furnace doesn’t malfunction. The average lifespan of a furnace flame sensor is about five years. If the sensor has stopped working properly before that time then it’s possible that it just needs to be cleaned.

How Does Flame Sensor Become Dirty?

The flame sensor is sensitive to any type of buildup on the device. If the furnace is located in an area of the home or establishment that’s susceptible to the accumulation of dust then the buildup can make its way to the sensor and stick to the surface, interfering with the device’s readings. Additionally, just like with the burning of car fuel, carbon can amass from the ignited fuel in the furnace and leave a coating of carbon deposits on the flame sensor that will need to be cleaned off. There are a couple of ways to tell if the flame sensor might be dirty. If the furnace won’t ignite or if it lights for brief periods before shutting down on its own, then examine the flame sensor and look for any layers of soot or dust on the appliance.

How To Clean It?

To clean the flame sensor properly, you’ll first have to shut off the furnace and remove the sensor. Remember that the thermostat is a temperature control device and turning it off does not cut off power to the entire furnace. To turn the furnace off, flip the toggle switch to the “off” position. If you can’t find the toggle switch, then use the circuit-breaker box to cut off power to the furnace. Flame sensors are usually attached to the furnace with a hex-head screw. Once the screw is removed, the flame sensor should easily slide out. Use a piece of light grit sandpaper to gently clean off the metal rod until the buildup has been cleared as much as possible. Use a paper towel to remove any dirt left behind after the sanding.

How To Avoid This Problem?

While some dust and carbon deposits are to be expected with these devices, you can lessen the amount of buildup by keeping the furnace and the areas around it clean and clear of any excessive accumulation of dirt that can make its way to the flame sensor. However, furnaces are typically installed in areas that attract dust and it’s nearly impossible to completely prevent buildup. Aire One Heating and Cooling in Toronto can help with the maintenance and protection of your heating system. Contact us if you have any problems with your Flame Sensor and we will be more than happy to assist you!

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