• Pete McGrath

HVAC Compressor Autopsy: Find Out What Went Wrong to Prevent Future Failures

“Bring that compressor back to the shop and tear it down”, comes the order from Mechanical Service Corporation president Harry Hartigan.

When a compressor fails prematurely, getting someone to replace it is only half the battle. Having someone determine exactly why a compressor failed is just as important. MSC performs autopsies on all failed semi-hermetic and screw compressors so a repeat failure can be avoided – and a good deal of the time, it can. More often than not, compressors are killed by system problems, not by a defect in the compressor itself.


Did the compressor overheat? Was it oil or refrigerant slugging? Could it have been an electrical failure? Was it lack of lubrication, or maybe an acid burnout?


Through the years, MSC has found out why a compressor failed for countless clients and made changes to their systems in order to prevent a disruptive and very-costly cycle of repeated compressor failures, upset, and finger-pointing.


Tearing down a compressor isn’t quite as easy as taking out a wrenched ankle in the old board game Operation from long ago. After the compressor is torn down, motor windings are examined for nicks and cylinder walls are examined for scoring. Sometimes, pieces of pistons and connecting rods are found in a heap in the bottom of the oil pan. A thorough post-mortem, along with a complete set of refrigeration readings at the start-up of the new compressor, makes all the difference in the world for the life span of the replacement compressor.