The compressor is one of the most important parts of an air conditioning system. Located in the condenser unit – the outdoor unit – it’s responsible for compressing the refrigerant. This process will change the refrigerant from a gas to a liquid state so that the condenser coil can effectively remove heat from it. With little or no compressor oil, however, you may experience the following problems when running your air conditioning system.

#1) Unusual Noises

If you hear unusual noises coming from the compressor, it may be low on oil. A low oil level can cause unusual noises, such as knocking, banging or humming. Compressors contain multiple moving parts. As the oil levels begin to drop, friction will increase between these parts. You may then hear the compressor’s parts as they rub against each other due to this friction.

#2) Excessive Vibrations

Strong or excessive vibrations can be a sign of a low compressor oil. The next time your air conditioning system turns on, walk around to the side of your home and find the condenser unit. The condenser unit is a large box-shaped container that houses the compressor, condenser coil and other related parts. If the compressor is low on oil, it may vibrate excessively.

#3) Seizing

One of the most telltale signs of low compressor oil is seizing. Seizing means the compressor locks up. Without sufficient oil, the compressor will succumb to friction. All of this friction will wear down the compressor to the point where it seizes up.

#4 Poor Cooling Power

If your air conditioning system isn’t cooling your home like it used to, the compressor may be low on oil. Air conditioning systems work by capturing heat from the interior of a home and transporting it to the exterior of the home. The compressor’s job is to compress the refrigerant, which is the medium for this heat transfer process, at the condenser unit. When it fails, your air conditioning system will struggle to release heat outside of your home at the condenser coil, resulting in poor cooling power.

#5) Loss of Refrigerant

Another sign that your air conditioning system is low on compressor is a loss of refrigerant. Compressor oil helps to reinforce the mechanical seals, such as O-rings or gaskets, that contain the refrigerant. With little or no oil, refrigerant may work its way past these mechanical seals and, thus, leak out of the compressor.