What Can Cause An Air Conditioner's Compressor To Overheat?

If your air conditioner is constantly turning off for no apparent reason, the compressor may be overheating. Overheating can severely damage the compressor, so modern air conditioners will switch off when they realize that the compressor is becoming too hot.

To understand how overheating can happen, you'll need to first know a bit about how air conditioners work. The refrigerants that are used inside air conditioning systems (the older R-22 or the newer R-410A) were chosen because they're excellent at transferring heat. Refrigerant travels from your outdoor unit through an expansion valve, which turns it into a gas. It flows through the evaporator coils near the blower fan, and the fan constantly blows air from your home onto it. The refrigerant extracts heat from the air, which cools down your home.

Afterwards, the refrigerant travels back to the outdoor unit, where the compressor forces it back into a liquid state. This process heats up the refrigerant considerably. In its heated state, it flows through the condenser coils in the outside unit. A fan in your outdoor unit constantly blows air over the refrigerant, which causes it to lose its heat to the outside air. After that, it flows to the inside of your home in order to cool your air again.

Since your air conditioner compressor is overheating, it's very likely that the problem lies in your outdoor unit. Your refrigerant is unable to lose any heat to the outside air, causing it to become increasingly hotter until the compressor overheats. To learn what can cause this to happen, read on.

1. Malfunctioning Outdoor Fan

If the fan in your outdoor unit isn't spinning, the refrigerant isn't able to efficiently transfer heat to the outside air. Check your outdoor unit to make sure that no leaves or branches have fallen into the fan, which can prevent it from operating. If the fan is clear, its motor may have failed—you'll simply need to replace it.

2. Obstructed Outdoor Unit

Similarly, refrigerant can't lose heat to the outside air when the outdoor unit has poor airflow due to an obstruction. Make sure nothing is covering the outdoor unit. If you have bushes growing near your outdoor unit, you'll need to trim them.

3. Dirty Condenser Coils

Since the outdoor unit is constantly exposed to dust and dirt, it's common for the condenser coils to become dirty. Dust and dirt covering the condenser coils will act as a form of insulation, trapping heat within the refrigerant rather than letting it escape. Turning your air conditioner off and gently washing the condenser coils with a hose will clean them.

4. Very Low Refrigerant

Finally, your compressor can overheat if you have almost no refrigerant in your air conditioning system. The compressor generates a substantial amount of heat while it runs. Under normal operating conditions, most of this heat is transferred to the refrigerant that passes through the compressor. When there's no refrigerant flowing through it, the compressor will eventually overheat and shut down. You'll need to call an AC repair service to recharge your refrigerant and look for leaks.

An overheating air conditioner compressor is an annoyance, but is usually easy to fix. If cleaning the condenser coils and the area around the outdoor unit doesn't solve your problem, call an AC repair service to inspect your air conditioning system. A technician will be able to find the root cause of your overheating air conditioner and fix it, allowing you to cool your home again.

To learn more, contact a resource like Arctic Air Heating & Cooling.