How to Find a Leak in a Central AC System
- 1). Turn on the air conditioning system for 10 to 15 minutes to build up the pressure of the gas in the system before turning it off and looking for the leak. If there is slight cooling coming from your vents, then most likely you have a slow leak, and there is still some gas in the system, making finding the leak fairly straightforward.
- 2). Mix some soap and water in a bucket. Dish soap works well for this purpose.
- 3). Soak a sponge in the soapy water and apply the mixture over the compressor. Compressors are the most common site of leaks as they have many moving parts and many seals that can wear out over time. Look for any small bubbles forming, especially where pipes enter the compressor or where metal meets metal.
- 4). Locate the condenser coil. This is generally located outdoors with a fan mounted beside it to blow air over it for the purpose of removing heat. Turn off the system to deactivate the fan and wash it down with soap and water while looking for the formation of bubbles. Concentrate on the inlet and outlet pipe of the condenser coil.
- 5). Locate the evaporator coil. This is the coil that cools rapidly and is located either inside your furnace or just after a fan in the ductwork. Apply soap and water in the same fashion as with the compressor and condenser coil. Just before the evaporator coil is the essential expansion valve, a small metal adapter on the inlet side of the evaporator coil, check this for leaks as well.
- 6). Check the hoses connecting these elements if no leak has been found yet, although leaks in these passageways should not occur unless damaged by abrasion or pinched with something else. When the leak is found, either replace that part of the system, or if possible just the seal, usually a rubber o-ring where pipes meet each other.
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