When it’s hot outside and you try to turn on your AC to get your house cooled down, only to find that the air conditioner won’t come on, you’ll know something is wrong right away. But the opposite situation is also a problem: when your air conditioner comes on… and it won’t turn off. Not only does this mean you’ll have a house that’s too cold, but it’s a major waste of energy and puts enormous amounts of stress on the AC. What’s causes this to happen?
Ice along the evaporator coil
Look to see if there is ice developing along the indoor evaporator coil. Sometimes people dismiss this sight as a natural consequence of the air conditioner cooling down the air. It isn’t! If you see ice on the coil when the AC won’t turn off, it probably means the system has lost refrigerant to a leak somewhere. The air conditioner is unable to lower the temperature enough to complete its cooling cycle, so it will keep running. A refrigerant leak needs to be fixed right away, since it can lead to catastrophic damage to the compressor. Call repair technicians as soon as possible.
The problem may be a thermostat that has faulty wiring. One of the wires to the thermostat is responsible for turning off the fan/compressor. If this wire loses its connection, the system will keep running. The thermostat might also be sensing incorrect temperatures and not shut off when it’s supposed to. Professionals can fix both thermostat problems to restore proper operation.
Dirt on the condenser coil
The condenser coil is the outdoor coil that’s responsible for dissipating heat to the outside of the house. If dirt has built up on it, it will trap heat inside the AC and force the system to continue to work to reach its target temperature. You should call professionals to clean off the coils properly.