Why Does an Air Conditioner Blow Cold Air for 15 Minutes Then Quit?

Compressor

• If your air conditioner blows cold air, turns off and then turns back on again after few minutes, then the room might have reached the designated air conditioner cooling temperature. When the set thermostat level is reached within the room, an internal sensor reads the temperature and turns the compressor off, leaving the fan running to circulate the air in the room. When the temperature in the room raises, the compressor turns back on to activate the cooling element. The compressor and cooling element continue to run, until the temperature in the room reaches the desired thermostat setting again.

Coils

• If the coils within the air conditioner unit freeze, the unit might shut-off after a few minutes as a safety measure. Before turning the unit back on, allow the coils to thaw. Set the air conditioner fan to high and raise the thermostat to expedite the defrosting process. Allow 30 minutes to an hour for the coils to thaw before gradually lowering the thermostat.

Drainage

• If the air conditioner unit features a "Dry" cycle and is ductless, the unit allows collected humidity to accumulate in an internal drain pan or drainpipe within the unit. When the drain pan or drainpipe is full, you must drain the unit. If the full drain pan or drainpipe isn't drained, the unit shuts off as a safety measure. Empty the drain pan before you turn the unit back on. Unplug the unit and move it to a drainage area. Unscrew the drain cap on the lower back of the unit, remove the plunger from the drainpipe and allow it to drain outside or in a bathtub. After the unit is fully drained, plug it back in.

Power

• If the unit blows cold air for 15 minutes and suddenly shuts off, unplug the unit to reset the connection. There might have been a power surge, which affected the electrical setup of the unit. Plug the unit back in and press the "Reset" button on the AC plug. If the unit fails to turn back on, inspect the breaker that controls the unit. If the breaker switch is in the "Off" or middle position, flip the switch back over to the "On" position. Turn the AC unit on.