Changing a Furnace Filter

“Is it cold in here? I don’t think the furnace is keeping up.” Ever said these words on a cold winters day? Well, it might be because the furnace filter is restricting air flow to the furnace, and this tutorial will show how to change it easily.

In order to effectively do this job correctly, a new furnace filter the correct size for the furnace will be needed and the thermostat turned to the off position. The correct size can usually be found written on the furnace or in the owner’s manual. It can also be found on the filter that is to be removed.

Locating the old filter is one of the first things that needs to be done. It is usually located on the side of the furnace inside a portion of the cold air return ducting. On occasion, it can be found on the top or bottom depending on the make and model of the heater itself. Some contractors may install a tin cap that is placed over the filter.

Next, if a tin cap is present, remove it exposing the old filter. Pay special attention to which direction the airflow arrow is pointing, this is the direction the new filter will have to be installed. If the new one is not put in correctly, the furnace will still operate but the new filter will blind over much faster than if it installed correctly.

After removing the cap, take hold of the old filter. Pull up or out, depending on the orientation of the furnace, until the old filter is completely removed. You will want to have a trash bag to place the used, dirty filter in to minimize the mess.

Then, the same way the old filter was removed, slide in the new one in the exact same way. Be sure to push it down until it feels as though it is thoroughly seated. There should be minimal gaps around the filter.

Last of all, place the tin cover back over the filter slot and turn the thermostat back on, reigniting the heater. The furnace should now have the correct air flow to function correctly.