Heat pumps rely on refrigerant to transfer heat from indoor spaces to outdoor spaces and vise versa. Whether you’re warming your home or cooling your home with a heat pump, refrigerant will move through its components to facilitate the transfer of heat and, thus, regulate your home’s indoor temperature.

Refrigerant, however, can leak out of heat pumps. As levels of refrigerant begin to drop, your heat pump will no longer be able to cool or warm your home. What causes refrigerant leaks in heat pumps exactly?

#1) A Cracked Refrigerant Line

A cracked refrigerant line can cause this heat-transferring chemical to leak out of your heat pump. Like air conditioning systems, heat pump systems have refrigerant lines. They are typically made of copper. Over time, refrigerant lines can degrade or even crack. If the crack extends completely through the line, it will allow refrigerant to escape.

#2) Worn Seal

A worn seal can cause your heat pump to leak refrigerant.  Refrigerant will travel through multiple components when your heat pump is running. It will travel through the indoor coil and the outdoor coil, for instance, and it will travel a pair of refrigerant lines. Seals are often used on the mating surfaces of these components to protect against leaks. If a seal fails, refrigerant may leak around the mating surface.

#3) Improper Installation

Improper installation is a common cause of heat pump refrigerant leaks.  Heat pumps are complex systems. With their dual-purpose function – they can heat and cool your home – they require proper installation. If your heat pump was installed improperly, it may leak refrigerant.

#4) Corrosion

Corrosion can cause refrigerant leaks in heat pumps. Refrigerant lines are typically protected against corrosion. They can tarnish due to oxidation, but they generally won’t ruse or corrode. With that said, the non-copper components in your heat pump may be susceptible to corrosion. As corrosion eats through a refrigerant-carrying component, it can create a leak.

#5) Outdoor Coil Damage

Damage to your heat pump’s outdoor coil may result in a refrigerant leak. Heat pumps have an outdoor coil that’s similar to that of an air conditioning system. The main difference is that the heat pump’s outdoor coil can operate as an evaporator coil or a condenser coil. Regardless of which mode it’s currently operating in, the outdoor coil will contain refrigerant. Any physical damage to the outdoor coil may then create a leak.