There are a lot of potential failure modes for an air conditioning system, but few are as annoying and potentially costly as a leak. An AC unit that is leaking outside can be a significant annoyance, but an interior leak can quickly cause costly water damage repair bills to pile up. Even worse, these leaks may not be detected for some time, leading to hidden damage that can easily spread from the original source. All of this can add up to a real nightmare for homeowners, so it's important to recognize these issues and deal with them promptly.

Why Do AC Units Leak?

The most important thing to understand about "leaks" in air conditioning systems is that the air conditioner itself isn't really losing water. In fact, your AC system doesn't use plain water for anything. Instead, leaks are really a condensation problem. Your AC unit functions by moving refrigerant between your indoor and outdoor units, transferring heat from inside of your house back to the outside environment. As the refrigerant passes through the evaporated coils, it is cooled and water from the surrounding air condenses onto the coils themselves.

An AC unit that is operating normally has a condensation pan and may also include a pump. The purpose of the pan (or reservoir) is to collect condensation and move it away from the house. In some systems, this water is carried through a regular drain line. If this isn't possible, then a pump is used to move the water out of the reservoir.

Recognizing AC Leaks

It's not always obvious that you have a leak, although severe problems can cause your AC system to stop working altogether. This usually happens because water is not properly being moved out of the condensation reservoir, either because the pump has failed or because the drain line has become clogged. AC systems are equipped with overflow sensors that prevent the water level from becoming too high, and once these are triggered, the system will no longer operate.

More alarming is when water begins to drip from vents in your home. There are a few reasons that this can happen, and they mostly depend on how your particular AC system is set up. In cases where the indoor unit is located high up (such as in an attic), a backup at the condensate pan can actually cause water to enter the ducts. Uninsulated ducts may "sweat" as well, condensing water on their own as the cold air traveling through them cools the metal ductwork.

Dealing With Leaks

Fortunately, many water leaks are simple problems that you can deal with yourself. If you notice an excessive buildup of water in your reservoir or if the AC unit ceases to function because of the overflow safety, the best thing to do is check the drain for clogs. If your unit makes use of a condensate pump, however, then it's probably time to call in a professional for a more accurate diagnosis of the problem.

Leaky vents can be tougher to deal with since this particular problem often points to installation issues. While adding insulation is not necessarily difficult, it's best to have a technician evaluate the condition of the ductwork to determine the underlying cause of the problem.

Whether you choose to solve the problem yourself or call in a pro, the most important thing you can do for any water leak is to deal with it promptly. HVAC issues can sometimes be expensive to fix, but their cost pales in comparison to the cost of repairing major water damage.

Contact an air conditioning repair company like Universal Refrigeration for more information.