Four Reasons Why a Good Compressor Can Go Bad

Posted July 25, 2022 by in Lifestyle

For many technicians, it might be difficult to identify the cause of a compressor failure in an air conditioning system. This is due to the fact that problems can arise from a number of causes, and by the time they are identified, it is frequently too late for the compressor. Here are some reasons why a good compressor can go bad.


One of the main causes of compressor failure is overheating, which is typically brought on by a lack of refrigerant in the system. The suction gas temperature will gradually rise in an air conditioner system with a low refrigerant charge, whether as a result of a leak or an undercharge.

The compressor windings won’t be able to be sufficiently cooled if the vapor temperature at the compressor inlet is too high. The collapse of winding insulation might easily be caused by the compressor’s constant overheating. Compressor oil can become polluted and acidic as a result of the deterioration of insulation, compression, heat, and time. Additionally, a low refrigerant charge lowers the suction gas velocity needed to return oil vapor to the compressor. Low velocity can cause lubricated parts like bearings, journals, and compressor mating surfaces to prematurely mechanically fail.

When a compressor is operated beyond its intended parameters, damage can develop quickly and, if left unattended, can eventually result in compressor failure. Make careful to follow the manufacturer’s installation, charging, and commissioning instructions to avoid overheating. Smart air conditioner technology can also be useful to prevent damage to the compressor. Aircon with smart technology can identify problems and send out alerts before they affect the compressor’s efficiency and life expectancy. Being able to identify and address functional problems before a system fails is a major benefit.

Refrigerant charge and piping

Overcharging a system can lead to liquid flood back, which happens when liquid refrigerant enters the compressor while the system is operating, yet undercharging a system can cause the compressor to overheat. When liquid refrigerant is returned to the compressor crankcase, even in little amounts, it will flash and literally “boil the oil,” causing the creation of oil foam. Oil foaming can and can cause lubricated surfaces inside the compressor to wear out earlier than necessary. Larger flood back amounts can also cause irreversible mechanical failure due to the compression of liquid refrigerant.

Slugging, which happens when liquid refrigerant enters the compressor during transitory situations like charging, startup or defrost operations, can also be caused by an overcharged system. Internal parts may break as a result of this condition, impairing heating and cooling efficiency and/or causing compressor failure. Limited slugging can cause minor compressor damage, but excessive slugging and flooding can cause an abrupt catastrophic failure. Ensure that the system is charged adequately in accordance with the manufacturer’s instructions taking into account the flow control devices.

Fortunately, refrigerant issues may frequently be resolved and avoided by adhering to instructions for refrigerant piping and making use of equipment like accumulators and crankcase warmers.


In a cooling system, contaminants like moisture or oxidation can cause chaos, which can eat away at the compressor windings. When installing refrigerant piping, proper practices should be followed to prevent impurities from entering the system, which could affect the lifespan of the compressor.

High-temperature brazing is a technique used in the majority of air conditioning and heat pump systems to join copper refrigerant pipework and fittings. A very low-pressure nitrogen purge must be supplied when brazing because the interior of refrigerant lines must be kept to a nearly sterile condition during installation. As a result of nitrogen purging, oxygen is replaced, which stops oxide production. Oxides are pumped through the system in the form of scale when sufficient nitrogen purging is not done. This may cause strainers, expansion valves, and refrigerant oil to become acidic, which ultimately results in an early compressor failure.

In order to prevent any debris, such as dirt, dust, sand, and other pollutants from entering the lines, it is essential to maintain the piping ends sealed throughout storage and installation until brazing is done. It can be challenging to identify contaminants in a system until the compressor malfunctions, but monitoring pressure measurements can reveal their presence. 

Incorrectly sized and matched

Another problem that could affect the compressor is a split system where the indoor coil is the incorrect size for the outdoor coil. For instance, if the indoor and outside coils are mismatched in size, the compressor may have liquid flooding back.

Additionally, contractors should always carry out a thorough load assessment for the structure to guarantee that the system is sized appropriately for both interior and outdoor design conditions. Systems that are excessively big or small would put undue strain on a compressor, leading to subpar space cooling.

Poor installation and maintenance procedures are to blame for the majority of the compressor issues mentioned above. An incorrect installation which was followed by the neglect of maintenance accounts for the majority of compressor failures.

The system’s long-term reliability can be increased by doing proper routine maintenance, which enables professionals to spot problems before they have a chance to have catastrophic effects. A system may be kept running as intended with routine maintenance that includes simple tasks like changing filters to guarantee proper airflow to the indoor and outdoor coils.

Check out to find common symptoms of a broken compressor, so you can immediately contact professional help to fix the problem.

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