How To Clean Furnace Sensor?

Are you tired of constantly replacing your furnace sensor? Are you experiencing issues with your furnace, such as it not turning on or turning off too frequently? It’s possible that your furnace sensor is dirty and needs to be cleaned. In this article, we will guide you through the steps on how to clean your furnace sensor, allowing you to save money on repairs and keep your furnace running efficiently.

A furnace sensor plays an essential role in regulating the temperature of your home. It detects the temperature inside the furnace and sends signals to the control board to turn on or off the furnace. Over time, the furnace sensor can become dirty, leading to inaccurate readings and causing your furnace to malfunction. Cleaning your furnace sensor is a simple and cost-effective solution that can extend the life of your furnace and keep your home comfortable all winter long.

If you notice that your furnace is not working properly, or it’s turning off and on, it could be due to a dirty furnace sensor. To clean it, follow these simple steps:

1. Turn off the power supply to your furnace.
2. Locate the sensor, which is usually near the burner assembly.
3. Remove the sensor from the furnace.
4. Clean the sensor with a soft cloth or emery cloth.
5. Reinsert the sensor back into the furnace.
6. Turn on the power supply and test the furnace.

Regular cleaning of the furnace sensor can improve the efficiency of your furnace and extend its lifespan.

How to Clean Furnace Sensor?

How to Clean Furnace Sensor?

Cleaning your furnace sensor is an important maintenance task that should not be overlooked. A dirty sensor can cause your furnace to malfunction, leading to costly repairs and even potentially hazardous situations. In this article, we will walk you through the steps to properly clean your furnace sensor.

Gather Your Materials

The first step in cleaning your furnace sensor is to gather all the necessary materials. You will need a soft-bristled brush, a clean cloth, and a can of compressed air. You may also want to wear gloves and eye protection for added safety.

It’s important to note that you should never use water or any type of liquid cleaner on your furnace sensor. Moisture can damage the sensor and cause it to malfunction.

Turn Off the Power

Before you begin cleaning your furnace sensor, you need to turn off the power to your furnace. Locate the power switch or circuit breaker and turn it off. This will ensure that there is no electricity running through your furnace while you clean the sensor.

It’s also a good idea to wait a few minutes after turning off the power to allow the furnace to cool down before you begin cleaning.

Remove the Sensor

The next step is to locate the sensor and remove it from the furnace. The sensor is typically located near the burner assembly and is attached to the furnace with a screw or clip.

Once you have removed the sensor, inspect it for any visible signs of dirt or debris. Use the soft-bristled brush to gently brush away any dirt or debris on the surface of the sensor.

Clean with Compressed Air

After brushing away any visible dirt or debris, use the can of compressed air to blow away any remaining particles. Hold the can upright and use short bursts of air to avoid damaging the sensor.

Be sure to blow air through the small holes on the sensor as well to ensure that they are clean and clear.

Reinstall the Sensor

Once you have finished cleaning the sensor, it’s time to reinstall it back into the furnace. Be sure to reattach the sensor securely with the screw or clip.

After the sensor is reinstalled, turn the power back on to your furnace and test to make sure it is working properly.

Benefits of Cleaning Your Furnace Sensor

  • Improved furnace performance
  • Increased energy efficiency
  • Reduced risk of malfunctions and breakdowns
  • Increased lifespan of your furnace

Cleaning Your Furnace Sensor vs. Professional Maintenance

While cleaning your furnace sensor is an important task, it’s not a replacement for professional maintenance. A professional HVAC technician can perform a thorough inspection of your furnace and identify any potential problems before they become major issues.

Professional maintenance can also help to ensure that your furnace is running efficiently and can save you money on your energy bills in the long run.


Cleaning your furnace sensor is a simple task that can have a big impact on the performance of your furnace. By following these steps, you can ensure that your furnace is running efficiently and safely.

Remember to always turn off the power to your furnace before cleaning the sensor, and never use water or liquid cleaners. If you have any doubts or concerns about cleaning your furnace sensor, it’s always best to contact a professional HVAC technician for assistance.

Frequently Asked Questions

Here are some common questions and answers about cleaning furnace sensors:

What is a furnace sensor?

A furnace sensor is a part of your furnace that detects whether the pilot light is on. It’s an important safety feature that ensures the furnace doesn’t continue to produce gas if the pilot light is out. If the sensor is dirty or malfunctioning, it can cause the furnace to shut off unexpectedly or not turn on at all.

Cleaning the furnace sensor is a simple task that can be done with a few basic tools. It’s important to do this regularly to ensure your furnace is working properly and to prevent any potential safety hazards.

How do I know if my furnace sensor needs cleaning?

If your furnace is turning on and off frequently, or if it’s not turning on at all, it may be a sign that the sensor needs cleaning. You may also notice that your furnace is producing a lot of soot, or that the flame is yellow instead of blue. These are all signs that the sensor is dirty and needs to be cleaned.

Cleaning the sensor is a simple process that involves removing it from the furnace and wiping it down with a clean cloth. You can also use a fine-grit sandpaper to gently remove any buildup on the sensor.

Can I clean the furnace sensor myself?

Yes, you can clean the furnace sensor yourself. However, it’s important to follow the manufacturer’s instructions and to turn off the power to the furnace before attempting to clean the sensor. You should also wear gloves and protective eyewear to prevent any injuries.

If you’re unsure about how to clean the sensor, or if you’re not comfortable doing it yourself, it’s best to contact a professional HVAC technician to do the job for you.

How often should I clean my furnace sensor?

You should clean your furnace sensor at least once a year, preferably before the start of the heating season. If you have pets or if there’s a lot of dust in your home, you may need to clean the sensor more frequently.

Regular cleaning of the furnace sensor can help prevent unexpected shutdowns and extend the life of your furnace. It’s also an important safety measure that can help prevent carbon monoxide leaks and other hazards.

What other maintenance tasks should I perform on my furnace?

In addition to cleaning the furnace sensor, you should also replace the air filter regularly and have the furnace inspected by a professional HVAC technician at least once a year. This can help ensure that your furnace is running efficiently and safely.

You should also make sure that the area around the furnace is clear of any flammable materials, and that the furnace is properly ventilated. If you notice any unusual smells or sounds coming from your furnace, or if your energy bills are higher than usual, it’s important to contact a professional technician to diagnose and fix the problem.

Furnace Cycling On and Off – Flame Sensor Cleaning – Furnace Troubleshooting

In conclusion, cleaning your furnace sensor is an essential part of maintaining your heating system. Neglecting to clean it can lead to malfunctions and even a complete breakdown of your furnace. By following the steps we have outlined, you can easily and safely clean your furnace sensor and ensure that your heating system runs smoothly.

Remember to always turn off your furnace before attempting to clean the sensor and use a soft-bristled brush to avoid damaging the delicate components. Additionally, be sure to check your furnace filter regularly and replace it as needed to further improve the efficiency and longevity of your heating system.

By incorporating these simple maintenance tasks into your household routine, you can avoid costly repairs and extend the life of your heating system. Don’t wait until your furnace breaks down to take action – start cleaning your furnace sensor today and enjoy a warm and comfortable home all winter long.