Think Ahead When Repairing Refrigeration Systems
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Think Ahead When Repairing Refrigeration Systems

Aug 04, 2023

Repairing refrigeration systems can be difficult at times. Simple repairs can become complicated, and complicated repairs can become even more complicated. While repairing a system, you should try to look ahead and avoid common issues that can make repairs more difficult.


• Repairing HVACR

• Troubleshooting HVACR

• Refrigeration

For example, when working on older systems, sometimes the stem of an old service valve can leak when you change its position, either going from a back-seated to mid-seated position or from a mid-seated position to a back-seat. This could make finishing a repair complicated. Although it is not always possible to prevent this complication, there might be times when it can be avoided if you think ahead.

Recently, I needed to change out a compressor on an older system. It had a suction service valve that was mid-seated and an access tee to allow for a low-pressure switch connection. There was also a service valve on the outlet of the receiver that looked like it had not been exercised in years. There were no other valves on the system. The suction valve was not really an issue since it had a Schrader tee in place, and the valve stem did not need to be touched to change out the compressor.

However, the service valve on the receiver looked like it could be an issue. If its stem leaked, it would require changing out the entire receiver, which I did not have on my truck. So I could take a chance and hope the valve stem did not leak, or I could think ahead and not use the service valve. I decided to add a temporary saddle valve on the liquid line for recovery and then remove it and braze in a permanent access tee — a little extra work, but this ensured the job could be completed without any major complications.

Another opportunity to think ahead is when replacing electrical components. It is always good practice to either mark the wiring being removed or draw a picture referencing the connections. Sometimes I find it also helpful (as in the case of changing a contactor or defrost timer) to unmount the original component, leaving it wired, and then mount the new component and transfer the wiring from the old to the new. This is not always possible or practical, but when it can be done, it is helpful.

When replacing a cap tube, thinking ahead could help prevent some problems. I found it a good practice to leave the ends of the cap tube sealed while installing the cap tube through the case cabinet. Sweeping a little nitrogen through the cap tube while cutting and cleaning its ends and inserting into its connections is also a good practice.

When replacing a fractional horsepower compressor, sometimes the electrical terminals are in a tight location. This can make it a little more difficult to make these connections and re-install the terminal cover. However, you can prevent this difficulty by pre-wiring the compressor with a pig tail before setting it in place and then connecting the pig tail to the original wiring.

There are many other examples of how thinking ahead can help prevent complications. Taking a little extra time on a repair, looking for possible complications, and coming up with a potential workaround can make finishing a repair much easier.

Joe Marchese is an author, instructor and HVACR service contractor. He can be reached at [email protected].