Do You Clean Furnace?

Do You Clean Furnace?


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Do You Clean Furnace?

Do You Clean Furnace?

Do You Clean Furnace? You should. Many people are intimidated by their Furnace and Air Conditioner, but it is merely just another piece of Equipment that needs some Maintenance and TLC from time to time. While you may need to call in an expert if your unit is not operating properly, regular Maintenance is something that most Homeowners can handle on their own.

Although each Make and Model is somewhat different, there are some simple Steps that are somewhat universal for Maintaining most Furnaces.


Materials & Supplies Needed:

  • Replacement Furnace Filter


Purchase Furnace Filters at:


Tools & Supplies Needed:

  • Safety Glasses
  • Mechanics Work Gloves
  • Shop Vac (or Standard Vacuum) with Crevice Tool Attachment
  • 1/4” Drive Ratchet, Short Extension, Various Sockets
  • Mini Wire Brush
  • Small Channel Lock Pliers
  • Lightweight Oil


In order to purchase any Tools & Supplies Needed, see the appropriate page in any of the drop-down pages under:  Home – Garden:  Tools and Equipment List  in my Top Menu.

Scroll down the list to find the correct item. You will find an explanation of that item, as well as, links under each item, which direct you to my Recommended Suppliers for you to check out their offerings.





Step-by-Step Instructions


Step 1 – Assess the Project


Begin your Assessment with looking at your Furnace Filter. If it is dirty, you need to change it. You can tell if it is still efficient by holding it up to a light. If the light shines through at least ½ of the Filter than it is still OK. If not, then, it is time to change it. The Filter size will be listed on the cardboard side of the Filter.


To remove the old Filter, complete as follows:

  • Turn OFF the Blower Switch next to your Furnace (if you have one) or turn off the Circuit Breaker (or remove the Fuse) for the Furnace.


  • Next, take the Front Panel OFF of the Furnace.


  • Lift up the Front Cover slightly and pull it toward you to remove it.


  • Remove the Lower Panel by gripping the sides and pulling it toward you.


  • Lift up any Spring Holder holding the Filter in place, and slide the old Filter out.


  • Inspect the Cardboard Sides for size information and write down dimensions on a piece of scratch paper.


If you have a reusable, cleanable, Foam Filter, the instructions for cleaning will be found in Step 6.


The rest of your Assessment will merely be looking at how dirty and dusty everything else is. This should always be cleaned annually.


Step 2 – Create a Materials & Tools Needed Sheet


The only Materials and Supplies that you need for this Project is a Furnace Filter. You can either consult your Furnace Maintenance Manual if it is handy, or you will need to remove the old Filter and check the size, which should be clearly marked on the Filter.

Add to your sheet any Tools and Supplies that you will also need, but do not currently have.


Step 3 – Calculate Project Cost

Step 4 – Order Your Materials & Tools Needed

Step 5 – Inspect Your Delivery


After reviewing the information here, additional information to complete these first (5) Steps is found in the page:  5 Steps for Project Management.  Simply click on that link and you will be directed there.

After completing those first (5) Steps, return to these Instructions and continue on to Step 6.


Step 6 – Clean Reusable Furnace Filter or Replace Filter


If you have a reusable, cleanable Furnace Filter, take the Filter out, clean it, dry it, and reinstall. If your Filter is the disposable type, simply replace it with a new one.


  • Remove your reusable Filter, carefully noting the way it is installed, so that you can replace it the same way. Air flow will always come from the outside of your Furnace, flowing to the inside (toward your Squirrel Cage Motor).


  • Once your reusable Filter has been removed, take your Shop Vac and vacuum the entire surface, removing any dust.


  • Then, if your Filter has a separate foam covering, remove it and rinse it thoroughly under warm water, occasionally squeezing it out to remove all dust. Once the squeezed water runs clear, place the foam covering in an appropriate place to allow it to fully dry before replacing it. This may require you to have to flip it over once the first surface area is dry.


  • Once dry, replace the foam covering onto your Filter.


  • Reinstall your Filter, being careful to install it correctly for proper air flow.


Step 7 – Vacuum the Furnace Cold Air Return


With your Filter removed, take your Shop Vac (or Standard Vacuum Cleaner) with the Crevice Tool Attachment in place, and vacuum the Cold Air Supply Grate, inside and out. This is the Grate that is located closest to your Filter. When you are finished, replace your Filter.

You should also vacuum all Cold Air Return Grates which are on every floor of your Home. These are usually located at the end of Hallways.


Step 8 – Vacuum the Furnace


Make sure that your Blower Switch is OFF (located next to your Furnace if you have one) or turn off the Circuit Breaker (or remove the Fuse) for the Furnace. Vacuum all the rest of the Furnace, beginning from the top and working your way down to the bottom. Vacuum all parts that contain dust, including: Furnace Walls, Burners, Wires, Blower Motor Ends, Floor, etc.


Tip:  Be careful not to disturb any wire connections when vacuuming.


Before vacuuming your Furnace, complete the following steps:

  • Turn OFF the Blower Switch next to your Furnace (if you have one) or turn off the Circuit Breaker (or remove the Fuse) for the Furnace. Next, take the Front Panel  OFF of the Furnace.


  • Lift up the Front Cover slightly and pull it toward you to remove it.


  • Remove the Lower Panel by gripping the sides and pulling it toward you.


Then, take your Shop Vac, starting from the top, down, vacuum everything in your Furnace, being careful not to disturb any Wiring.


Step 9 – Clean the Blower Motor Squirrel Cage Fan


Remove the Blower Motor and Clean the Squirrel Cage Fan.


  • Most Furnaces have a ‘Squirrel Cage’ Fan attached to the Blower Motor. This type of Fan provides quieter and more efficient air flow. It is a circular Fan with multiple fins which can become caked with dust over time. These fins should be cleaned every 2 – 3 years, or more often in a very dusty environment or if you own any pets.


Tip:  Most Blower Motors will have a Capacitor attached to the outside of them. Be very careful not to touch those connection or you will get a shock.


  • Before removing the Blower Motor, you will need to first make sure that all power is OFF to the Furnace, as was instructed in Step 7.


  • Then, trace the Wires from your Blower Motor to the Junction Box. These Wires will need to removed from the Junction Box before attempting to remove the Blower Motor.


  • Either take a Picture with your Smart Phone of the Blower Motor Wires or mark down on a piece of scratch paper, indicating the Wire Colors and their locations. This will help to insure that you will replace the Wires correctly when the cleaning has been completed.


Tip:  Be very careful not to touch the Terminals on the Capacitor, which is usually attached to the Motor Housing Cover, or you may get quite an Electrical jolt.


  • Now you will unbolt the Motor.


  • Usually, there are only (2) small Bolts holding the Blower Motor in place. These will be located near the front of the Motor on either end, attaching the Motor Frame to the Furnace. Using your 1/4” Ratchet, small extension (if needed), and correct Socket size, remove the (2) Bolts and set them off to the side.


  • Once the Wires and the Bolts have been removed, the Blower Motor should just slide out toward you. Be careful, as these Motors tend to be rather heavy. Once removed, set the Motor down on the Floor, and using your small Wire Brush, clean all of the Motor Fins. Then, take your Shop Vac and vacuum up any dust. You can also take a damp Rag, and wipe each of the Fins when you are finished removing all of the heavy dust and dirt.


  • Next, vacuum both ends of the Motor, including any Wire Coils that are there.


  • Then, check to see if your Motor contains any Oiling Ports. These Ports will be located at either end of the Motor, allowing a few drops of Oil to be added to keep the Motor Bearings lubricated. It will usually be a small Plug, or possibly a small, hinged, pop-up Door. Older Motors will have these. Newer Motors will not have these, as they usually have sealed Self-Oiling Bearings.

  • If you do have the Oil Ports, remove the Plugs (using your small Channel Lock Pliers), and place 3 – 4 drops of lightweight Oil in each Port. Use either a 10W Motor Oil, Machine Oil, or Sewing Machine Oil. Do not put more than the recommended amount of Oil into each Port, or you may damage the Motor.


  • Once the Motor has been cleaned and Oiled, you should reinstall the Blower Motor, reversing the removal process. First, slide it back into place, screw in your Bolts and tighten them snug, being careful not to over tighten and strip out the Bolts. Then, reattach your Wires according to the color coded positions that you previously recorded.


Step 10 – Replace Your Furnace Doors and Test


Once all of the cleaning has been completed, replace both your lower and upper Furnace Doors, turn the Power back on, and test your Furnace by turning up the heat on your Thermostat.


  • If you are unsure about the cleaning of your Furnace, you can always hire a Professional to come and do the work for you. You can find reputable Contractors & Handypersons at any of the following:



Nice Job! Your Furnace should give you another Year of Good Service!


Please take the time to leave a Comment or ask a Question in the Comments section below. Let me know how your Project went.



CJ Dodaro

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