How to Clean a Furnace?

Hello, fellow homeowners and HVAC enthusiasts! Today, we will dive into an important aspect of home maintenance – cleaning your furnace.

As a key part of your HVAC system, a well-maintained furnace not only ensures energy efficiency but also contributes to better indoor air quality.

We will explore the importance of cleaning, how to safely prepare for the task, the process of cleaning both the exterior and interior, including the combustion chamber, and finally, some words about blower motor maintenance.

Follow along to learn how to keep your furnace running optimally.

Why is Cleaning Important?

Regular cleaning is essential to ensure the efficiency of your furnace. A clean furnace operates more effectively, reducing energy bills and ensuring better heat distribution.

It also helps to prevent costly and potentially dangerous issues like poor combustion or a cracked heat exchanger.

Cleaning your furnace also maintains better indoor air quality by reducing the amount of dust, pet hair, and other debris that can circulate through your home.


Before starting, you need to prepare and consider several safety measures.

Safety Considerations

First, shut off the electrical power and gas source. The control panel will have a switch for the electrical power, and the gas shutoff valve should be located near the incoming gas pipe.

Gather Necessary Materials

You will need a few items for the cleaning process: a vacuum cleaner with a brush attachment, clean cloth or damp cloth, and a shop vac for heavier debris if needed.

Shut Off Power and Gas Source

As a safety precaution, always shut off the power and fuel supply to your furnace before cleaning. This helps prevent accidental shocks or gas leaks.

Exterior Cleaning

Once you’ve prepared, you can begin cleaning the exterior of your furnace.

Remove Debris from Outside of Furnace

Start by removing any debris on and around the furnace base. Use a vacuum cleaner to remove dust and pet hair, focusing on the blower compartment and air ducts.

Vacuum Surroundings with Brush Attachment

Use the brush attachment on your vacuum cleaner to gently clean the surface of the furnace, including the blower fan and the exterior of the burner assembly.

Clean Access Panel and Electrical Wiring Connections as Needed

Wipe down the access panel using a clean cloth. You can also clean the electrical wiring connections with a damp cloth if needed.

Interior Cleaning of the Combustion Chamber

After cleaning the exterior, you’ll need to clean the furnace’s interior components.

Open Access Panel to View Interior Components

Open the furnace access panel. This should provide you with a view of the interior components, including the combustion chamber, gas valve, and burner assembly.

If you are not confident in your ability to clean your furnace, then always call a licensed HVAC technician to help you instead of taking on the task yourself.

Clean Pilot Light, Burners, Flame Sensor, and Other Parts As Necessary

Use a vacuum cleaner to remove dust and debris from the pilot light, burners, flame sensor, and hot surface igniter. Make sure to check and clean the furnace filters as well.

Check for Proper Flame Color and Size

After cleaning, turn the furnace back on to check the burner flames. They should be blue and steady. Yellow flames indicate that the burners are dirty and require further cleaning.

Blower Motor Maintenance

The blower motor is a crucial part of the furnace as it helps distribute the heated air throughout your home. Regular cleaning is essential to maintain its performance.

Check the blower belt for any signs of wear or tear. Lubricate the shaft bearings, if necessary, and clean the motor bearings.


Regular cleaning and routine maintenance of your furnace are crucial to keep it running efficiently and safely. Although the process might seem daunting at first, with a bit of practice, you can easily handle this task.

Remember, proper maintenance not only extends the life of your furnace but also contributes to a healthier living environment. And of course, if you come across any issues or are uncomfortable performing these tasks, don’t hesitate to contact a professional HVAC technician!

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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