The furnace is the primary heating source of a central air system. Keeping the furnace well maintained will prolong its life, improve energy efficiency, and reduce the chances of a safety hazard. Every fall schedule a service professional to complete a full maintenance checklist. Although it is possible for savvy DIY homeowners to tackle this checklist, it is best handled by professionals with the proper equipment.
The heating process in the furnace is a combination of combustion and heat transfer. The process starts with the intake of a fuel (eg natural gas) and air. The combination is ignited by the burner and drawn into the heat exchanger by negative pressure from the draft inducer. Air from the house is pushed passed the heat exchanger. The air from the house absorbs energy from the heat exchanger and cools the combustion gases. The air then returns to the living spaces of the house through the duct work. The combustion gases are expelled through the flue to the outside.
One of the most important aspects of routine furnace maintenance is keeping the unit clean by changing the air filter. For most modern homes the filter is located at the air intakes. For older homes a lot of times the air filter is located just before the furnace.
Changing the air filter is one of the easiest ways to keep the furnace clean and operating efficiently. Filters that are too dirty will clog up the air intake and force the furnace to work harder. Using a cheap filter will not capture all dirt and dust particles. Dust collecting on the heat exchanger creates an unwanted layer of insulation.
Furnace Maintenance Checklist
Annual Maintenance Servicing
Every fall a professional maintenance servicing should be scheduled. They have special tools and meters that help to clean up all components and optimize performance. Here are the normal steps for furnace maintenance:
- -Remove the power and fuel supplies for safety. Use safety glasses, gloves, and surgical mask for any cleaning steps.
- -Remove the access panel to the combustion chamber. Use a wire brush to remove soot buildup and vacuum up the debris.
- -Examine the flue for any leaks. Seal small holes with foil tape. Corrodes flues should be replaced. It is important that it is completely sealed to prevent poisonous gases, like carbon monoxide, from leaking into the house.
- -Replace the oil filter. Make sure to close the oil valve while replacing the filter.
- -A professional will use a special meter to measure the exhaust gases to check the efficiency of combustion. The fuel to air ratio should be adjusted so that all of the fuel is burned up.
- -Remove the access panel to blower compartment and clean out all the dust. Then remove the oil port caps on the side of the blower motor and slowly drop in oil without overfilling (i.e. make sure it is the correct oil for your unit).
Air Filter Replacement or Cleaning
Replace disposable air filters every 2-3 months. For households will pets consider pet specific filters and replacing the filters every 1-2 months. Reusable filters should be cleaned monthly. Check the manual for the filter to see if you can use a detergent or other cleaning solutions. While cleaning or replacing the air filter clean the edges of the air intake.