Before each cooling season, it is recommended that central air conditioners get a professional tune-up. This is the biggest step to preventing major malfunctions in an AC unit.
Probably the most important step that can be done by a homeowner is to clean or replace the air filter every month. Electrostatic filters are the best. Do not run the unit with the filter removed. Check the owner’s manual for filter cleaning procedure. Let a washed filter dry completely before reinstalling it.
Every month, especially during the summer months, remove any leaves or debris from outdoor condenser units.
Help keep the outdoor condenser fan running efficiently by cleaning the fan blades and the coils before each cooling season. (Always turn off the power before attempting anything other than superficial cleaning). Remove the fan grill and the fan blades. Gently brush off debris from the blades. Then uncover the condenser coils and gently brush the dirty side. Then hose water from inside the unit, using plastic bags to protect the motor and other components. Also check the base pan (under the unit) and remove any debris that has accumulated there as well.
If the condenser fan makes a clicking or grating noise it may indicate that the blades may be striking an obstruction. If a blade becomes bent, do not try to straighten the blade. A straightened blade may become unbalanced and can loosen the fan motor or hit the condenser coil. Replace a bent blade with a new blade. After replacing a blade, make sure the fan blades rotate freely and don’t wobble. If fan often becomes loose, apply a drop of thread-locking compound.
Keep vegetation at least 2 feet away from outdoor units on each side and above. Aim grass clippings away from the unit when mowing the lawn. During the fall, keep the fan grill free of leaves.