Nearly 90 percent of all central-air service calls are related to leaks. Although these leaks tend to be relatively small, if left unchecked they can cause a tremendous amount of damage, especially if the air handler is installed above a ceiling and can drip downward. But most homeowners don't realize that a vast majority of leaks can be easily repaired without calling a service technician.There are main reasons a central A/C system leaks. First, there's a crack or hole in overflow drain pan. Second, the air filter is clogged with dirt. Third, the condensate line is plugged up.The first cause—the overflow pan—is easily detectable by simply using a flashlight. The pan is a piece of equipment that catches any condensation from the A/C unit; if you're noticing a leak, carefully inspect the overflow pan for damage. Check each corner, along the outside edges, and, of course, directly above the wettest spot. Small holes and cracks can be patched with epoxy glue, but it's usually best to replace a damaged overflow pan.

The second culprit—a clogged filter— can be avoided by changing the A/C unit's air filter on a regular basis. Most filters are designed to be used for one or two months, but you should inspect the filter every month during the cooling season. If the filter appears dirty, replace it immediately. A dirty filter will cause ice to form on the unit's evaporator coils, and when that ice melts, it drips water.2001 honda civic ac compressor fuseThe third reason—a stopped-up condensate line—is the most common cause of A/C leaks. yanmar gas powered air conditioning unitsThe condensate line drains condensation from the overflow pan to the outside or directly into a drainpipe. ac unit buzzing fan not workingWhen the line is clogged, water backs up and floods the overflow pan.

Another reason to keep the condensate line clear is that most modern A/C units are equipped with a water-overflow cutoff switch, which automatically shuts down the A/C system if it detects a clogged condensate line. The switch helps prevent water damage, which is good, but most homeowners don't know why their air-conditioning system suddenly shuts down and they call a service technician.There are a couple different ways to clear a clogged condensate line, including using a wet/dry vacuum to suck out the clog. But my favorite method is to use a product called Mighty Pump. It's a powerful hand pump that can be used to suck or blow lines clear. Invented by Stuart Oakner, a licensed air-conditioning contractor with more than 30 years experience, the Mighty Pump is available online for about $60.Still, don't wait for the condensate line to become clogged. You can avoid costly damage and expensive service calls by regularly clearing it out. And once the line is clear, you can help prevent the accumulation of slime, algae, mildew, and bacteria by pouring a little chlorine bleach down the line once every four to six months.

Celebrate Air Conditioning Appreciation Week with this gallery  from Magnum Photos. Ever wonder about the water that drips down from air conditioners as an unwelcome sidewalk surprise when you’re walking to work? In 2011, Forrest Wickman looked into the reason why ACs are so leaky, and if there’s anything unsanitary about the water that’s dripping down on you. The original article is reprinted below. Walk down any city sidewalk on a hot summer day, and you're bound to get wet—and not just when it's raining. Water drips from window AC units, especially on muggy days, and this unpleasant drizzle can fall into your hair or even onto the lip of your morning coffee cup. Is all that dripping water sanitary? Yes, as a general rule. Most of the dripping from air conditioners is just condensed water vapor that comes from the air inside the building. Window air conditioners are designed to drain this water from the back, raining it down on any unsuspecting pedestrians below.

In most ways this water is exactly like rain (which also forms from condensed water vapor) or the moisture that collects on a cool can of soda, and it's typically no more harmful. However, in rare cases small amounts of water can be left to stagnate inside the air conditioner, making it a breeding ground for bacteria. On a hot and humid day, a window unit can drip up to 2 gallons of water, which accumulates on its evaporator coil as it cools and dehumidifies the air. (Very little condensation gathers on the exterior side of an AC, which tends to be warmer than the air around it.) This coil, like many plumbing pipes used for drinking water, is made of copper (which is also what makes air conditioners so heavy), and it's much cleaner than you might expect from looking at a dusty AC filter. While copper can be unhealthy in high doses, the condensate from air conditioners seems to be low in minerals and dissolved solids. In a properly functioning air conditioner, the water drips down from the coil into a condensate pan and then exits the unit through a drain or tube.

However, a clog in this drain or tube can leave a puddle to accumulate inside, which is an ideal environment for many types of harmful bacteria. In particular, a 1976 outbreak of Legionnaires' disease was caused by bacteria that spread out of the air conditioning system at Philadelphia's Bellevue-Stratford Hotel. (That's how the disease got its name: Many of the victims were attending an American Legion convention.) While Legionella is known to thrive in the cooling towers of large air conditioning systems like the one at that Philadelphia hotel, it does not seem to grow in smaller units. Furthermore, dripping water isn't really stagnant, so it's extremely unlikely that the water raining down on pedestrians would be infected. The water that drips from air conditioners is probably even safe for drinking. (It's certainly more potable than the drinking water in many countries.) Still, for the reasons mentioned above, it's best not to tilt your head back for a draft. If you're looking for a better use for your air conditioner's condensate, the Explainer recommends using it to water your plants.