A window air conditioner is a good choice for apartment dwellers who can't install a permanent A/C unit, and for bedrooms and other such rooms; you can run the window unit for needed cooling in that small space without turning on the home's central unit, saving money and electricity. To troubleshoot some common problems with window air conditioning units, first understand how they're typically made, and then you can better understand how to fix those problems.
How window air conditioners are designed
A window air conditioner is a bit different than a central unit; the window unit will have two separate sections, one in the front for parts that sit inside the house. These parts include an evaporator coil that gets cool, the fan that blows cold air into the room, the thermostat, and a filter.
Behind a panel that separates those sections, the parts that are meant to sit outside the window include the compressor, a fan that blows air across that compressor and its coil, and a metal pan that collects and drains evaporated water.
Water inside the home
If water is dripping from the front panel of the air conditioner, it may be that the pan meant to catch and drain condensation is not tilted to the outside of the home properly. Don't just tilt the air conditioner itself down or outward, as this can increase the risk of it falling out of the window, but remove the panel between the two sections and note if the drip pan has come loose and needs tightening. This can ensure the pan itself tilts outward.
Unit cycles off too quickly
If the air conditioner unit comes on but then switches off too soon, check to see if the thermostat has slipped away from its connectors and is sitting too close to the evaporator coil. If so, the thermostat will read a cooler temperature than it should and will switch the unit off too quickly. You also want to ensure the front of the thermostat is not covered, such as by drapes, as this can also interfere with its ability to read the temperature of the room.
Unit won't come on at all
First, ensure that the unit has not tripped a circuit in your home. If the circuits are working, you might want to have the internal wiring of the unit checked. A loose wire to the thermostat or other controls can mean that the unit won't switch on; usually, a wire can be tightened or replaced very easily.
Contact an air conditioning maintenance company for more information and assistance.