Understanding your furnace

Understanding how a high efficiency furnace works is a simple concept. At the request of a thermostat natural gas or propane is piped to a burner which is located inside a combustion chamber. In this chamber, fuel is mixed with air which is then ignited by a pilot light.

A blower inside the unit pulls cool air in through air ducts and passes it through a metal heat exchanger. Here it is heated by the burner then returns warm air back into your living space by way of ductwork.

The exhaust gases are vented out through a flue or chimney.

Forced air systems can be added on for special air conditioning needs. A unit can be installed to cool and dehumidify the air. An electronic air cleaner can clear the air of dust and other particles and a humidifier can be added to return moisture to dry winter air.

Furnace Maintenance

When doing an annual “self” tune up and maintenance, you will want to concentrate on the three basic parts. The heat sensor or thermostat, the heat exchanger and the blower.

The first step should be to analyze the furnace itself. Be sure there is no build up of soot or any combustion residue on the furnace or the areas surrounding it.

Turn the thermostat up to ignite the unit. Check that the flames in the burner are blue in color and burning steady. If they appear either yellow or flickering, it is an indication of poor combustion. If this is the case it is wise to contact a professional technician to fix the problem.

Once it is determined that the flame is burning efficiently, turn the thermostat down and allow the furnace to cool down. Turn the circuit breaker to the furnace to the off position. When the furnace is completely cooled, remove the sides and using a vacuum, remove any dust that has accumulated. Clean the blades of the blower and all areas that are not reachable with the vacuum with a damp rag. If your blower fan is equipped with oil cups at the ends of the central shaft, give them a few drops of oil. Some units are sealed and do not require oiling.

If the blower fans are driven by an electric motor and fan belt, check the condition and tension of this belt. When checking the tension, there should be about an inch of play in it. If you have more or less, loosen the electric motor mounts and adjust it by moving the motor to create the correct tension. The belt should also be free of cracks which is caused by the dry heat. If the belt is cracked or worn, replace it with a belt of the same size.

Once completed, replace the side panels and turn the breaker back on.

The last step in your furnace maintenance is changing the filter. During the heating season it is wise to replace the filter once a month.

Remember the Furnace Flue

Remember when cleaning your furnace it is wise to also check the flue. If the flue is blocked, cracked or crumbling, you will not get the maximum efficiency out of your heating unit. The easiest sign that your chimney is deteriorating are small pieces of flue in the clean out. This may be actual pieces of like a sand like material that is orange or reddish. If a check shows that any of these problems exist in your flue, it is best to reline your chimney with a stainless steel chimney liner. The installation of a stainless steel liner will prevent further decay of the inside of your flue and provide ease in cleaning. It will give you added safety against carbon monoxide and chimney fires.

You can install a Stainless Steel Liner Yourself!

Although self maintenance and tune ups should not replace that of a professional, it is good practice to get into. A professional cleaning can run upwards of $100.00 but is well worth the money. The peace of mind that it will give you knowing your family is safe is priceless.


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