Do you get angry when you see a higher heating bill? How about when you find out that a simple task like not changing your furnace filter is what is costing you that extra money? It may be an annoying part of home maintenance, but if you don’t change your filter regularly, your furnace could overheat and shut down because it can’t get enough air to cool off. To keep your furnace (and you) from working harder just to heat your home, we’ve provided a basic guide to replacing your furnace filter.
When should you replace your furnace filter?
A dirty furnace filter will affect indoor air quality, so check it about once a month. If you can’t see light through your filter when you hold it up to a lamp, you should replace it. If you have animals, burn candles frequently, open doors and windows often, or smoke in the home, you’ll probably need to change your filter more often.
How to replace your furnace filter
- Turn off the furnace.
- Locate the filter. Consult your manual if you don’t know where the furnace filter is. Most filters are either
- In the blower compartment. To access, remove the furnace cover or lift up the lid to get inside.
- In the return air vent, built into the metal ductwork.
- Remove the existing filter. Pull on the tab or lip of the filter frame to slide it out. When you pull the old filter out, have a garbage bag on hand and slip it in carefully to avoid scattering dust around.
- Note the airflow direction. Your filter will have an arrow indicating which way it should be placed to properly filter the airflow from your ductwork. The direction of the arrow should be pointed toward the furnace fan. Mark this on the exterior of your furnace with a permanent marker. That way, you’ll always know which way to install your new filters.
- Determine the filter size. Take a picture of or write down the filter size printed on the cardboard frame. You can also find the size in your furnace manual or use a measuring tape to determine its dimensions: height, width, and thickness. If your filter has an aluminum or plastic frame, it’s reusable, meaning you can clean it with a vacuum and water.
- Purchase a filter. You can find them at home stores, hardware stores, or online.
- Install the new filter. Look for markings on your new filter that tell you which side should face the furnace to correctly filter air flow, then insert accordingly.
- Keep the receipt from your new filter and tape it to the furnace so you know when you’ll need to replace the filter again. Make sure to turn the furnace back on after you’ve replaced the filter.