When a customer’s compressor goes down, determining that it failed and finding a replacement are fairly simple and common processes. Determining why the compressor failed on the other hand, might not be so easy. “Why did the compressor fail?” This is an extremely important question the service technician has to be able to answer. The alternative is not a pleasant scenario. Replacing the original failed compressor without finding the cause of failure almost always leads to the subsequent failure of the replacement compressor as well. The last thing your customer wants to hear is that their mechanical system is down because of a repeat compressor failure.

Without knowing the cause of failure, the replacement compressor almost always fails, and its replacement fails, and its replacement fails, etc. etc. . Unfortunately in our industry it’s a situation we experience far too often. No one wins when replacing the compressor two, three, or four times. Not the customer, not the contractor, and not the supplier. Customer loses their cool, contractor loses the customer, supplier loses their reputation, and everyone loses money.

Wouldn’t it be nice if there was only one issue that could cause a compressor to fail? Unfortunately that’s not the case; there are numerous elements that can lead to a compressor failure. What makes it even harder to find what really caused the compressor to fail? During the initial inspection, the compressor has most likely already failed and the system is down as well.

A few possible causes for compressor failure can be detected shortly after the installation and start-up of the replacement. These include liquid coming back to the compressor, high discharge temperature, incorrect voltage, or high return gas temperature. The technician should devote some time investigating and identifying why the original compressor failed.

What to look for during inspection:

- amount of superheat at the compressor inlet

- running suction and discharge pressures

- temperature of the returning refrigerant

- discharge gas temperature

- compressor’s amperage draw

- applied voltage to the compressor

NOTE: The Start-Up Report is a valuable diagnostic tool and helps to ensure all the proper readings are taken for a thorough evaluation.

The cause of failure might not be clearly recognizable immediately following the start-up of the replacement compressor. The problem might not be detectable until after the system has had the opportunity to go through a complete cycle. It may not develop until after the system has been up and running for some time. Therefore, the technician should closely monitor the system’s operation until the cause for the original failure can be clearly determined.

Replacing a repeat failure is a costly, no-win situation for all involved. It directly impacts the profit margin of the customer, contractor and supplier. It can cause irreparable damage to the reputation of the contractor and/or the supplier (depending on the nature of their business, the customer too). Finding the root cause of the problem, repairing the issue, and preventing a repeat failure are all parts of the proper due diligence that will keep the customer, the contractor and the supplier content and profitable.


Why Did My Compressor Fail?


Electrical Failure