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HVAC Flame Sensor

How to Clean Furnace Flame Sensor

What is a furnace flame sensor? 

Flame is the safety equipment in the furnace system. Flame detects the temperature and sends data to the furnace burner. If the flame doesn't work properly and sends data to the furnace, then the flame sensors shut off the furnace. 

More important points about furnace flame sensors: 

  • Flame sensors are also known as heat sensors
  • The flame sensor is more efficient than a carbon monoxide detector
  • The flame sensor is made with a thin metallic rod
  • Clean your furnace flame sensor once a month regularly

Flame sensor location in your gas furnace:

  • Every manufacturer's furnace design is unique.
  • Open the panel of the furnace
  • Find out single wired attached with porcelain 
  • That is the location of the flame sensor in your home furnace

Why do flame sensors become dirty?

Carbon monoxide builds a layer on the flame sensor. That is why flame sensors become dirty. And sensors do not detect correct information and the furnace shuts down or leaks toxic carbon monoxide into your home. 

Why does my furnace keep shutting off?

  • The thermostat was placed too close to a heat source
  • Oversized furnaces quickly get high and low temperatures, because of an instant change in temperature 
  • The dirty flame sensor does not detect accurate temperature and inaccurate data can damage the furnace
  • Free airflow is needed for a good furnace. Learn more from the PartsHnC website for any queries.

How to clean and maintain the furnace flame sensor?

The maintenance part is very simple, you don't need any professional technician. 

  • Mostly a flame sensor goes bad because of carbon buildup 
  • Cleaning a furnace flame sensor is one of the best solutions

Before knowing the procedure of cleaning a furnace flame, we need to know about tools. 

  1. Hex driver: Hex's driver is also known as a socket set. This tool is used for installation or removing the panel.
  2. Wire wool: Wire wool is used to remove carbon monoxide from flame sensors. 
  3. Light-grit sandpaper: Light-grit sandpaper is also used to remove carbon monoxide. And this is essential for cleaning furnace flame sensors. 
  4. Microfiber rags: Microfiber rags are good for cleaning. It is a better option than a cloth or paper towel.

Why does my furnace keep shutting off?

  1. The thermostat was placed too close to a heat source
  2. Oversized furnaces quickly get high and low temperatures, because of an instant change in temperature 
  3. The dirty flame sensor does not detect accurate temperature and inaccurate data can damage the furnace
  4. Free airflow is needed for a good furnace. Learn more from the PartsHnC website for any queries 

How to clean and maintain the furnace flame sensor?

The flame sensor is a very important part of the furnace for safety purposes. Must check and maintain the furnace flame sensors regularly. Cleaning is necessary for good furnace health. The flame sensor must maintain a 100cm distance from the furnace flame. And follow all safety rules at the time of cleaning and replacing the flame sensor.

The maintenance part is very simple, you don't need any professional technician. 

  • Mostly a flame sensor goes bad because of carbon buildup 
  • Cleaning a furnace flame sensor is one of the best solutions

Before knowing the procedure of cleaning a furnace flame, we need to know about tools. 

  1. Hex driver: Hex's driver is also known as a socket set. This tool is used for installation or removing the panel.
  2. Wire wool: Wire wool is used to remove carbon monoxide from flame sensors. 
  3. Light-grit sandpaper: Light-grit sandpaper is also used to remove carbon monoxide. And this is essential for cleaning furnace flame sensors. 
  4. Microfiber rags: Microfiber rags are good for cleaning. It is a better option than a cloth or paper towel.

Flame sensor cleaning process:

  • Turn off all electrical connections that are connected with the furnace
  • In your furnace, open the door of the combustion chamber
  • Check any rust or dust on the flame sensor. If any rust or dust on flame sensors, then remove it with the help of light-grit sandpaper, cloth, or wool.
  • Clean furnace pilot and electronic igniter before changing furnace flame sensor
  • After replacing the furnace flame sensor, close the door of the combustion chamber
  • After cleaning the furnace flame sensor, close the outer panel
  • Check your work once
  • Turn on all electrical switches
  • And restart the furnace
  • Check whether Your furnace flame sensor is correctly working
  • If you have any issues with cleaning your furnace flame sensor, then just contact HVAC parts and accessories experts or call on (866) 963-0907 or send mail at [email protected]

Do this cleaning process once a year. Follow the correct process. Cleaning increases the life of the flame sensor. If you do not have technical-related experience, then clean it by yourself. Call a technician.

Furnace signs for bad flame sensor:

  • Color of burner flame:

You can see the color of your flame by opening the peephole. The color is bluish, so the working process of the furnace is correct. If the color is yellowish, then it would mean your gas is not correctly burned. It happens because of a dirty flame sensor or gas burner. 

  • Rusted flue lines

Flue system throughout the carbon monoxide outside of the home. If leaking happens, because flue lines rust and corrode, then carbon monoxide can not exit from your home. The bad flame sensor shut down the furnace operation. 

  • High energy consumption

Suddenly, your furnace consumes high energy and generates high electricity bills, then inspects the air filters. Clean your dirty air filters. Is your furnace still consuming high energy? Then there was a problem with the flame sensor. 

How to know if a flame sensor is bad or not?

  • Cut the power supply of the furnace.
  • Locate the flame sensor location.
  • Detach the screw.
  • Pull out the flame sensor
  • Observe the cracks on the flame sensor or take readings using a multimeter.
  • If you get 0.0 amps reading in a multimeter, then your flame sensor is damaged.
  • Repair or replace the flame sensor 

Troubleshooting process of flame sensor

The cleaning process of the flame sensor means troubleshooting for the flame sensor. Just refer to the above on how to clean the furnace flame sensor section. Do not clean with no knowledge. If your flame sensor cracked or crossed 20-plus years of age, then you need to replace it under technician guidance.

If you do not understand which is compatible with your gas furnace, then see the details of the old flame sensor or inform furnace professionals. To choose the correct one.

What is the working principle of furnace flame sensors?

Sensors are a more sensitive part of the furnace. Sensors are electric circuits and they detect a receiver's electromagnetic radiation and give output analog signals/digital signals. When sensors detect the wavelength from the source. This wavelength ranges from 700 nanometers to 1100 nanometers. 

Sensors contain four pins respectively.

Pin1: Voltage supply rages from 3.3V to 5.3V

Pin2: This is a ground pin

Pin3: This is an analog output pin

Pin4: This is a digital output pin

Most sensors are damaged due to dust and high temperatures. Make sure sensors must be cleaned and keep a small distance of up to 100cm from the furnace flame.

Straight flame sensor:

Product name: Flame Sensor For Lennox Part

Product number: 18G89

Manufacturer's name: Lennox

Similar products: 43594, SEN0007, 195292, SEN1951

90-degree angled flame sensor:

Product name: Flame Sensor For Carrier Part

Product number: 50HJ401431

Manufacturer's name: Carrier

Similar products: 17J56, SEN0297, 209973, 90H83

Cost of furnace flame sensor

The average cost of a Furnace Flame Sensor is between $70 to $270.

Cost for new furnace flame sensor/ Replacement of furnace flame sensor

The average cost is between $350 to $500 to buy a new furnace flame sensor.

The flame sensor is a very important part of the furnace for safety purposes. Must check and maintain the furnace flame sensors regularly. Cleaning is necessary for good furnace health. The flame sensor must maintain a 100cm distance from the furnace flame. Follow all the safety rules.

Want to buy the best quality furnace and furnace equipment parts online, then PartsHnC is the best website for any query contact us at [email protected], (866) 963-0907.

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