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How to Clean Furnace Flame Sensor

How to Clean Furnace Flame Sensor

 It is not difficult to keep a flame sensor in good working order. With the assistance of a few of the basic repair tools which you can easily find at home, you can quickly complete this task on your own with little effort.

1.  Turn off the heating system

You must ALWAYS turn off the HVAC unit or part before performing any repairs or cleaning.Alternatively, if your furnace does not have a switch button, you can shut it off using the toggle located on or near it, or by switching off the circuit breaker that serves your furnace.

2. Disconnect the Flame Sensor from the power source

Determine the location of a thin metallic rod-like element, which would be usually located at the end of the furnace and in the path of the burner.Most of the time, one or two 14-inch hex head screws hold the flame sensors in place. Simply unscrew the sensors from the burner bracket or assembly by gently sliding them out of the way.

3. Remove the Sensor from its case

To thoroughly clean some systems, it may be necessary to remove the wires that link the sensor. It is not required to disconnect the cords at this time, but this will provide you with greater space and flexibility when cleaning the sensor later on.For simple cleaning, gently sand the metal rod of the sensor with fine-grit steel wool or emery cloth to remove the carbon buildup that has formed over time.After that, wipe the metal rod off with a clean, dry paper towel to eliminate any change regularly and dust.

4. Re-assembly of the sensor

If you accidentally disconnected the wires that lead to the flame sensor, simply reconnect them once more. Then, using the hex screw/s that have been removed, attach the sensor to the burner bracket or assembly.


5. Inspect the furnace to see if it is now operational correctly

Restarting the furnace will perform a flame sensor test. If the furnace does not start straight away, wait a few seconds since it may be resetting or performing some start-upchecks while you wait. Leaving your furnace running for even one cycle will help ensure that the problem does not recur.

Changing out the furnace flame sensor

It’s possible that your furnace’s flame sensor is malfunctioning and needs to be replaced if you’ve followed the methods above and your furnace continues to shut off abruptly after being turned on. Sometimes the architecture of the furnace makes it difficult to remove the rods from the firebox. When you have your routine inspection and cleaning performed, the technician should take care of cleaning the flame rod as part of the service.

The flame sensor must be cleaned on a regular basis

Every two to three months, change your filters, and have your furnace completely cleaned once a year is a good rule of thumb.

A faulty flame sensor has the following characteristics:

1. Furnace burners come on for a few seconds before turning off.

2. The end of the sensor is covered with soot and other particles.

3.  The flame sensor’s tip is completely black in colour.

4. A crack has appeared in the porcelain/sensor case

Causes of flame sensor to become clogged

A fame sensor becomes dirty as a result of a number of factors. Flame sensors can malfunction, however the majority of the time they are not defective, but just dirty due to carbon buildup. For this reason, even the tiniest coating of carbon can cause a flame sensor to misread and shut down, due to its extremely low tolerance for fluctuations in the reading it takes.For simple cleaning, lightly sand the metal rod of the sensor with good steel wool or emery cloth to remove the carbon buildup that has formed over time. Remember that sandpaper should not be used on your flame sensor rod because it will cause it to become damaged. After that, wipe the metal rod down with a clean, dry paper towel to eliminate any remaining particles and dust.

A flame sensor that has failed is caused by the following factors:

As with any piece of equipment, a simple reason for failure could be a clogged flame sensor that has become ineffective over time. A blockage of dust or carbon could cause it to malfunction because it is such a sensitive sensor.

Cost of cleaning a flame sensor

Smoke detectors become too dirty and stop working properly, but these detectors can be repaired by thoroughly cleaning them. It will cost you anywhere from $80 to $250 to replace the flame sensor if too far gone and you must repair or replace it.

Similarity of flame sensor and an igniter

In your gas heating system, a flame sensor is a safety critical component. A spark or a hot surface ignitor will ignite the gas in your gas furnace during the ignition cycle, which is the first stage of the cycle. With each extinguishing of the gas flame, the flame sensor generates an electric current.

When my furnace turns on, it immediately turns off

After a while, the HVAC filter becomes clogged with dust and other particles. You will realize your furnace trying to run for a short period of time before turning off as a result of this short-cycling. Heat will build up in the room, and your furnace will shut down as a preventative measure. Furnace filters must be washed or tried to replace as required.

Manually restarting a furnace

1. Shut down the furnace’s power by removing the fuse from the circuit breaker panel in the circuit box.

2. If the button appears, press it down once it has been pressed once.

3. Replace the cover over the blower compartment and turn on the power.