Water Leaking From the Central Air Conditioner & the Unit Won't Turn On

Water Pan Leak

• A shallow pan beneath the evaporator on the air conditioner catches water that drips down during the evaporation process. Over time, these pans sometimes can rust or spring a hole and leak. Check the pan beneath the evaporator, which usually is housed in the basement or attic. If no water is in the pan, that's usually the sign of a leak. The pan should be replaced as soon as possible.

Drain Pipe Blockage

• The water from the drain pan runs through a drain pipe to the outside of the dwelling, where it evaporates. These pipes typically are composed of PVC pipe glued together. The pipe connects to the top of the drain pan into a threaded coupling. Mold and mildew can grow inside the pipes to block them, or they can become clogged with debris. Clean out the pipe by running a piece of clear tubing through to break up the blockage. Alternatively, a wet-dry vacuum hose can be connected to the pipe and the blockage suctioned out. Follow by rinsing it out with a mixture of bleach and warm water.

Drain Pan Float

• Some air conditioning units have what is called a drain pan float that will cut off the AC unit automatically if the drain pan becomes too full. These floats connect to the power switch for the AC unit. When the water in the pan rises, it carries the float upwards. When the water level reaches a certain level, it cuts off the power for the AC. To rectify this situation, bail out the water from the drain pan and unclog the line if needed.

Other Electrical Problems

• The leak from the air conditioner might have short circuited another line in the electrical system. Check the circuit breaker to see if any of the circuits have been tripped and reset them. Try to start the air conditioner again.