Common Sense Inspection
Unusual noises are a clue that something is wrong with your unit. You should notice if your air conditioner compressor makes loud noise when starting. Listen to the compressor and fans, so you know if they do not sound right.
Make sure the vents are blowing cool air. Inspect the insulation on the pipes and all metal surfaces. It is normal for some metal parts to develop rust but you can use a special paint -like VHT SP515 Quick Coat Clear Acrylic Enamel Can – 11 oz. – to prevent this from happening. Another way to prevent rust is to check for moisture.
US Department of Energy advises homeowners to inspect their air conditioners annually and perform preventive maintenance. Many local service providers offer this service for an affordable price. It may be better to leave this work to the professionals. The owner’s manual for the unit will outline suggested maintenance.
Clear Away Debris
The coils can only transfer heat if there is good air circulation around them. Clear away any shrubs, weeds, grass or other plants that are growing around the unit. Remove debris and leaves on or inside the unit.
Dusting the Coils and Fan Blades
Dusty coils will not transfer heat efficiently and any dust accumulated on the fan blades will interfere with the fan’s operation. Remove the cover to vacuum the dust off the coils. Wipe the dust off the fan blades and inspect the bottom of the unit for insect nests.
Cleaning and Replacing the Filter
Remove the filter and clean off any dirt, dust and debris. If you shake away the dust and the filter still appears dirty, replace it with a new one. Dirty air filters starve air conditioners of the air they need to function. This means the AC has to run for a longer period to cool the air. A clogged filter can cost you more on your electricity bill than it costs to buy one filter per year.
Freon Leaks and Recharging
Air conditioners need Freon to cool the air and sometimes they lose it through leaks in the system or diffusion over time. Study this video to learn how to check your system for a Freon leak. You will have to allow the unit to run for longer than 30 minutes to conduct this test. The best time to check the AC is on a hot day with high humidity.
You can also pick up a Freon leak detector like the Freon Halogen Refrigerant Gas Leak Detector R410A R134A.
The first step is to locate an insulated line with a metal surface and see if it is cold to the touch. If the line is warm and your unit is not cooling the air, your system is low on Freon. Before recharging the system, you need to check for leaks and make repairs or you will continue to have the same problem. If the system suddenly fails to cool properly, filling it with Freon is unlikely to solve the problem.