Maybe this belongs in the Pro's section, but since it relates more to Refrigeration, I will start here.
Basic background. I do supermarket refrigeration work for those who don't already know.
Mostly larger rack equipment, but in every grocery, there are smaller cases, and that is where my question is.
Call comes in as "case warm"
Arrive on site, no problem found. Either case is at temp or has been moved (unplugged) and when you restart it, it runs fine.
Run basic checks, superheat, charge checks, etc. Nothing abnormal found.
Now, I don't want to call my customers stupid (well, most of the time anyways. ), but I can PROVE that the case is operating properly before I leave.
How far do you take the troubleshooting? I am trying to be aware of the costs of troubleshooting and the cost of call-backs.