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WeatherMakers Heating, Cooling & Plumbing Blog

How to Change a Furnace Filter

One of the chores that sits atop every homeowner’s To-Do List is “Change Furnace Filter.” If you’re a new homeowner or new to a home with a forced-air furnace, you might not know how to change the filter, and most likely, you don’t see why you have to do it so often. Without a doubt, furnace filters need to be replaced regularly–monthly to every couple months–depending on the furnace you have and the type of filter you prefer. Changing your filter will keep your furnace running at peak efficiency and will help keep excess dust and pollutants from entering your home.

Follow these steps, and you’ll keep your furnace happy all season long. Not sure you’re comfy going under the hood of your furnace? Learn more about furnaces here.

Step 1 – Furnace Filter Replacement

Discover what type of filter fits your furnace. Some filters are seated into a small metal slot at the side of the furnace, while others are located behind metal screens or under panels. It’s always best to turn your furnace off before reaching into a furnace or removing a filter. You can do this at your thermostat by turning the “Heat” setting off or by turning the furnace off at the source via a switch that should be marked as “On” or “Off.”

Once the unit is off, remove the existing filter carefully, ensuring no filter materials remain. Look for an arrow on the filter indicating airflow direction. Using a permanent marker, draw the airflow direction on the outside of the furnace, so you’ll always know the right way to install the filter. You want to help air flow, not impede it, so pay special attention to this part. Then note the furnace filter size, which will be printed on the cardboard frame.

Note: A filter that has a plastic frame is a reusable filter, and you can clean it regularly using a vacuum or water. Just be sure to let it dry out completely before reinstalling. This can be a pain during the cold months, so consider keeping a spare reusable filter or vacuuming monthly and washing seasonally.

Replace the existing filter, turn on your furnace and go shopping!

Step 2

Buy the same filter or the same sized filter at your local home centre or hardware store. Feel free to choose a disposable or reusable model–both work just fine. Note that buying disposable furnace filters in bulk often saves money over buying them individually. As well, if you choose more affordable filters, just be sure to change them regularly and take extra care installing and removing them–they can be rather flimsy.

Step 3

Install the new filter so the arrow points the same way as it did on the filter that you removed. It should fit snuggly but not too snuggly. If something looks wrong, take a picture and consult a furnace technician or your furnace aisle pro at your hardware store. Once you’re certain you have the right filter in the right place facing the right way, replace any panels or covers. We recommend you place a note in your calendar reminding you when to perform your next furnace filter maintenance.

This one little chore done regularly can save you money and keep your furnace in top condition.

When should I fix or replace my furnace?

What does a furnace tune-up and inspection include?

Contact WeatherMakers about furnace issues.

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