We provide backup service for a supermarket chain with its own maintenance department. Their techs are not allowed overtime, so our calls are mostly overflow, or after hours calls. My techs dread these service calls for good reason. Here is a typical example:

The low temperature parallel rack is down and everything is thawing on Friday at 5 o'clock. Checking the log, the technician notices that refrigerant has been added regularly to the low temp rack for months. Leak-checking the machine room finds nothing - no lazy-man leaks. After 2 hours of checking the sales floor and underground piping and air handler he finds a loose flare connection on the pressure control of the condenser sufficient enough to explain the amount of refrigerant lost.

Confidently, he charges the rack back up with truck stock and the handy spare bottle in the machine room. "Maybe dinner can be reheated" he thinks to himself as he watches the temperatures pull down. Thoughts of dinner quickly disappear when he re-enters the machine room to discover that most of the EPR's and TEV's have been cranked wide open!

It is enough to make a grown man cry.

Has anybody else had that feeling during a service call?