Changing furnace filters:

Tools and Materials:      Filters
Filters of the throw away type will need to be replaced throughout the year. There are basically two types. The cut-to-size filter usually made of a fiberglass batten roll which can be cut to size to fit your furnace. Also Filter Elements that come in pre-made sizes framed in cardboard. You will need to determine the size and types needed for your particular furnace. (examples of pre-made filters are measured in inches 16x25x1, 10x20x1 and etc.). Determine the size and type before you go to the hardware. Both of these types of filters can be purchased at any good hardware store or heating and cooling supplier. Keep spare filters on hand. These filters differ also in quality. An inexpensive filter does not filter as well and will most likely need to be replaced more often (possible monthly). The more expensive filters can remove up to 97% of pollen and can have the efficiency of an electronic air filter. They may not need to be changed but every two to three months. Some furnaces will have permanent metal filter elements that can be washed and reused. These are the permanent-type and may never need to be replaced. As a reminder, write down the size of the filter for you furnace on a tag and tape it to your furnace access door. This way you won't forget the size. To change the filter first turn off the power to the furnace at the fuse or breaker panel. Also turn the switch off at the furnace. On a number of furnaces you will have to remove either top, bottom or both access panels from the front of the furnace. Release each panel with a sharp upward movement. As we had indicated above, there are two types of replacement furnace filters, the cut-to-size filter and the element filter.

The cut-to-size filter will usually lay in the furnace like a hammock, along the bottom, and can be removed by releasing it from each side and then pushing it to the middle. Fold the filter inward and then pull it from the furnace along with the filter holder. Roll out the hammock fiberglass material. Use a utility knife cut a section to size, then places this section of filter back into the holder. Slide the holder with filter back into the furnace. The holder is designed to hold the filter in place once it's in the furnace.

The Filter Element style of filter comes in different pre-made sizes. The filter is either pulled from its location within the furnace or from an outside slot located on the side of the furnace near the return air duct and blower motor. Either way they should slide out for replacement. These filters are pre-made in particular sizes to fit the required opening (Fiberglass filter framed by cardboard). Don't try the force the wrong size into the slot. If the filter element is made of metal wash it using a high pressure spray nozzle. Make sure you let it dry before re-installing it.

Once the filter is installed replace the access panels and restore power at the breaker panel and furnace switch.

Your servicing contractor should be able to help you with what areas of maintenance you could do. You may want them to change the filter while you watch. Then you can determine what maintenance items you could do yourself in the future.