
A good first maintenance task is to clean or replace the AC unit’s filters. If the filters become dirty or damaged in some way, this will strain the unit's motor, not to mention lower the quality of the home's indoor air.
Outside air conditioning units tend to get covered in all types of dirt and debris over the winter months so this is another area that will need attention to get them ready for summer. Clear all the leaves, branches, spider webs, and anything else that may have gathered around the unit. Then, remove the cover so that you can clean the inside of the unit as well. You should notice that there are hundreds of metal fins that surround piping coils. Very often these metal fins will become bent, but it is possible to straighten them out again using a special tool called a fin comb.
Next, you should check the AC unit’s drainage lines which are designed to draw condensed water away from the unit. The AC unit will not work optimally if the drainage lines become blocked so, as you clean the unit, be sure to check that these lines are not clogged and that they are firmly connected to the unit.
Lastly, if the air conditioning unit needs oil, check the operating manual to find out what kind of oil you need to use for your particular unit.