Lots of appliances in your home have filters. In fact, any device that conducts air or water should have some sort of filter in place to remove impurities and particulates. Changing these filters routinely can save you money, and keep you safe, which is why it’s helpful to know when they’re due to be replaced. Furnace filters should be replaced every two to three months; HVAC, ice maker, and water dispenser filters must change at least once a year. But that varies based on the manufacturer, so be sure to check your maintenance manual and not let it slide.