U.S. Inspect - Professional Home Inspections: Energy Heating and AC

Heating and Air Conditioning

(Return to Index)

Most heating and all air conditioning systems should be serviced annually, and many may require periodic maintenance to ensure a high degree of efficiency and energy savings.

Heat pumps should be serviced annually, at either the beginning or end of the heating or cooling season. The exterior compressor/condenser units should be kept clean and free of all leaves and debris. They should not be covered or otherwise boxed-in, which restricts the free flow of air, thus reducing efficiency and possibly causing damage to the compressor. Generally, the manufacturer’s recommendation is 2 inches clear all around and 5 inches clear above the unit.
Oil-fired heating systems should be serviced or cleaned annually to ensure that the barometric draft control is functioning properly, that the nozzle is sized properly and clean. An overall burner and system check should also be performed for efficient operation and functionality.

Gas heating systems require servicing every 2-3 years to ensure they are burning efficiently and to remove rust deposits. Little rust should be accumulating, even after 10 years. If more rust than expected is present, there could be a draft problem or draft-related inequities. The burner flame should be a stable deep blue with a somewhat greenish center; yellow/orange in the flame is an indication of inefficient combustion, while a wavering flame is an indication of a cracked heat exchanger introducing air and thus a waste of energy. However, residential gas units will always have yellow/orange tips. It is when the flame is yellow/orange or whitish that it needs adjustment.

Electric resistance furnaces and electric resistance baseboard units require little maintenance. Resistance furnaces should be serviced periodically to ensure that all of the heating coils are functioning and the fan motor is properly lubricated. Baseboard units should be vacuumed at least once a year to remove dirt and lint.
Air conditioning systems should be serviced every year at the beginning of the cooling season. The exterior compressor/condenser units should be kept clean and free of all leaves and debris; they should never be covered or otherwise boxed-in, and shrubs and hedges should be cut back. All of the above restricts the free flow of air, which reduces the gas to liquid process and efficiency of the system. In extreme cases, this may cause damage to the compressor. Window units should be removed during the heating system, because they allow an excessive amount of heat loss when they are left in.
Air filters on forced air systems, whether the filters are electrostatic, reusable, or disposable, should be checked at least monthly in the heating and cooling seasons and cleaned/replaced as necessary. A dirty filter will reduce efficiency tremendously and, in some cases, (e.g. heat pumps and air conditioners) cause possible damage to the unit (i.e. compressor).
All duct joints on forced air systems should be tight and sealed with duct tape. It is not unusual to find poorly fitted joints in crawl spaces or attics, which permit conditioned air to escape into these areas or draw in air from these unconditioned areas.
Ducts and pipes, which transport cool or hot air or water, should be insulated. The insulation should be at least 2 inches thick and, if cool air is being moved through the ducts, the insulation should have a vapor barrier on the outside because moisture only moves one way, from warm to cold. All seams of the insulation should be sealed with duct tape. The insulation used for wrapping ducts or pipes may be special duct wrapping insulation or standard fiberglass batts/rolls. Ductwork in attic areas is chronic conditioned air losers, even insulated ductwork. Ductwork is no match for the relentless temperature extremes that you find in an attic, even with adequate insulation.