How to Replace a Furnace Air Filter

Steps for Cleaning or Replacing a Hot Air Furnace Filter

By Mark J. Donovan

In order to keep your hot air furnace working efficiently and effectively you should replace its air filter every 3 to 6 months. Dust can quickly build up in a furnace air filter and impeded the flow of air through it. When this happens less air flows through your home’s heating duct work, thus causing your air furnace to have to run longer to get your home up to the desired temperature. As a result, this costs you more on your home heating bills, or air conditioning bills.

To replace a furnace air filter start by vacuuming around the furnace area to pick up any loose debris or dust that may have collected near it.

Next, shut off the main switch to the furnace so that it is not operating while you are changing out the furnace air filter. The on/off switch is typically located on or near the furnace.

After shutting off the furnace, open the air filter service panel. It is typically located adjacent to the intake/outtake fan blower. You may need a screwdriver to remove a few panel screws to get access to the filter.

With the air filter panel cover removed pull out the rectangular shaped mesh furnace air filter. Note that the furnace air filter may be orientated horizontally or vertically next to the blower fan.

Examine the furnace air filter to see if it is covered in dust and debris. If it is, then you’ll need to replace it or clean it. If it is clean, simply slide it back into the slot that you pulled it out of, reconnect the cover panel and turn the furnace back on.

If the furnace air filter is dirty and has a plastic or metal frame then you may be able to reuse the filter. Simply hose it down to rinse away the dust and dirt and lay it out to dry. Once it is completely dry reinstall it in the air furnace.

If the air filter has a cardboard frame they you’ll need to replace it. Take it down to your local home improvement center and find a replacement one of the same size. Again, insert the replacement furnace air filter into the slot next to the intake-outtake blower and reattach the cover panel plate. Once installed, turn the furnace on to complete the project.

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