Every time the season changes, you hear some expert mention how important it is to keep the air filter on your furnace changed monthly. So what is the big deal?
Changing the air filter is one of the simplest home maintenance items that a person can do. The filter is in place to clean the air as it passes through the furnace. If no filter is in place, all the dust and dirt from your home will pass unhindered through the furnace. It will find places to stick to, such as the blower wheel, the indoor air conditioning coil, and every other nook and cranny it passes along the way.
So what happens when a dirty filter stays in place too long? It will continue to stop dirt; enough so, that it will restrict air flow. When air flow is restricted, multiple things can happen. First of all, the blower will need to work harder to move the air. In heating mode, if the blower cannot move enough air, the heat buildup in the furnace can cause the temperature safety switches to trip, and shut down the furnace. If the air flow is restricted in air conditioning season, the indoor coil will form ice over it, causing the air to be completely blocked, while you are wondering why the air conditioner is not working.
As you can imagine, a system that is constantly under strain and working harder than it should, will have more problems and a shorter life span. Make it a habit to check your air filter every time the calendar changes.