Verify your furnace filter monthly

Your furnace filter prevents dirt, debris, pollutants, allergens and other impurities from entering your furnace and affecting your indoor air quality. If you have a bigger house, or a pet, your furnace filter will probably do more work in trapping the impurities, therefore, you should check it more often. Say, as often as once a month.

To know for sure if you need a new filter or can keep the one you have, hold it up into the light. If it has a darker color, grey or black, and you can’t see through it because of the dust and dirt build-up, it means you need to swap out your furnace filter.