If the filter of a furnace is not kept clean it will affect the functioning, efficiency and even the life of the furnace. Ensuring a clean filter means ensuring more durability, efficiency and improved air quality. It is not necessary to call a professional for filter maintenance as the job takes hardly an hour to complete. Follow the steps mentioned here to carry out the task and save money on maintenance charges. To start with the filter cleaning job you need to first switch it off and cut all power supply then you will have to find where the service panel is located. A service panel is located on the lower front of the furnace some units may have it on the side. With the help of a screw driver loosen all the nuts and bolts and then open it gently. Once you open the service panel you will be able to see the filter which is a mesh like thing located near the intake outtake blower. You can take the filter out by sliding either vertically or horizontally.
To check whether you need to replace the filter you need to try to see through it. If it is clear then you need not replace it just wipe it, put it back and then screw back the service panel. If the filter has collected enough dust then it need to be replaced with a new one (if it is a disposable one). If it is a washable filter then wash and let it dry completely before putting it back. Remember not to switch on the unit without a filter.