Changing your air filter is probably the single most easy thing you can do to prevent your furnace and your wallet from dying a slow painful death. Most air filters cost less than $20 and take less than 2 minutes to change. But if DIY isn’t your jam, no worries checking your air filter is part of Capital Heating & Cooling’s furnace and furnace and AC maintenance checklist. However, maintenance visits typically happen roughly six months apart and most filters should be changed every 30-90 days, depending on your lifestyle and the type and efficiency of the air filter.