Check out this month’s blog on the role of the compressor in your air-conditioning system to see whether you are at risk of becoming a compressor serial killer.

A hard-working motor often likened to an air-conditioning system’s “heart”, the compressor generates a hundred pounds per square inch of internal pressure and runs up to several hundred degrees pumping hot refrigerant gas from the evaporator into the condenser.

Costly and inconvenient, compressor failure is taken seriously by consumers and manufacturers alike. Interestingly, compressor problems are often not down to the actual machine itself. The results of one major manufacturer’s year-long teardown study found that one third of the returned compressors had been “killed” by system failures, which if corrected would have saved the compressor. If you replace a compressor without resolving any underlying issues with the system, then expect the same outcome!

There are many reasons a compressor can fail, but here are just a few to be aware of:

1. Overcharged system – If the evaporator is overloaded with more refrigerant than it can manage there’s a danger of “flooding”; liquid refrigerant entering the crankcase of the compressor when running, or “slugging” which is when the compressor’s cylinder becomes compromised by liquid refrigerant or liquid refrigerant and oil during an on-cycle.  Both of these conditions will cause the compressor to fail prematurely.
2. Undercharged system – A faulty or restricted TXV (thermostat expansion valve or metering device) can leave the evaporator starved of refrigerant which in turn forces the compressor to work harder, straining the system to the point of failure.
3. Improper lubrication – The wrong amount or type of oil used in a system will result in compressor failure. Insufficient oil leading to overheating and ultimately seizure is one of the most common causes of compressor failure.
4. Dirty condenser coils – A build-up of dirt on condenser coils not only compromises a unit’s efficiency it also makes it work much harder. Reduced heat transfer means the system can’t expel sufficient heat, pressure increases and ultimately the compressor will fail under the strain.
5. Contamination – This is the most common reason for a replacement compressor meeting the same demise at its predecessor. Setting up a new compressor in a dirty refrigerant system will make it susceptible to sucking up existing contaminants for example rust, sludge and foreign particles, including any discharged by the previous compressor, that have moved about and settled in the system.
6. Electrical Issues – Low voltage or poor connections can lead to the clutch slipping, which even at low to normal head pressures may cause the compressor to burn out. Another electrical issue can be caused by a problem pressure switch causing the compressor to rapidly cycle causing the clutch to fail prematurely.