One of your furnaces biggest enemy is dirt. It could waste fuel and drastically lower efficiency. Sometimes, it can also cause the furnace to overheat. Dirt affects three basic components of your furnace, so cleaning regularly is an important part if regular maintenance. You need to be cleaning the three parts of your furnace: the filter system, the motor and the blower.
Your furnace filter should be replaced or cleaned at the start of the heating season, and around once a month during periods you are continuously using it. When checking the filter, take it out and hold it up to the light. If it’s looking clogged, replace that with the same type and size filter, regardless of the length of time it has been used.
Disposable filters have a cardboard frame including a fiber mesh inside of it. If the size is needed, it should be printed on the edge of the frame.. An arrow that indicates the direction of airflow through the filter is also printed on the edge of the frame. Air flows from the return-air duct to the blower, so the arrow on the filter should point away from the return-air duct and to the blower.
A permanent filter is usually coated with a special filter-coating chemical. Clean this type of filter using the instructions, which are usually attached to the furnace housing. These are steps on how to replace your filter.
Look for a metal panel on the front of your furnace below the return-air duct, between duct and blower system. Make sure to look for the word “filter”, which should be on the panel, or it may form a lid or front of a boxlike projection on your furnace housing.
Slip the panel off of its holding hooks, or unscrew the panel from the box or furnace housing. On some heating units, filters are exposed; if this happens, just slip the filter up and out of the U-shape tracks that hold it in place.
Inspect and replace or clean the filter, depending on the type.
Clean the blower assembly, belts and pulleys to the blower and motor housing. Cleaning the blower is critical if your furnace has a squirrel-cage fan, because openings in this type of blower often become clogged with dirt. To clean your blower, remove the panel that covers the filter to gain reach to the blower or panel on the front of your furnace. This panel may be slip-fit on hooks or held in place by a series of retaining screws. Access to the inside of your furnace blower is usually gained by sliding out the fan unit, which is held on a track by screws.