Heating and cooling systems are usually trouble-free and easy to maintain. Efficient operation is a function of good regular maintenance. No matter what type of system you have, there are several things you can do to help keep it in top condition.
The air fliter - located in or next to the furnace - should be replaced regularly. To check the filter, take it out and hold it up to the light. If you see more than a dusting, replace it with a new filter of the same type and size, regardless of the length of time it has been used. The size of the filter is printed on the edge of the frame. The arrow should point to the furnace which is the direction of the air flow.
Bushes, ivy and other debris around the outside air conditioning should be cut back. Greenery can greatly reduce capacity and efficiency inhibiting the free flow of air into the unit. Also, objects within three feet above the unit can cause the hot air that has just been expelled from the unit to recycle back into it. This condition can greatly reduce efficiency and capacity, as well as hurt the compressor. Sometimes this state of affairs cannot be avoided, as in the case of a deck built over the unit. When it comes time to replace the unit this condition can be remedied.