This just happened last week. It truly belongs in the Trail of Tears.

A simple removal and replacement of a back room freezer case with a remote condensing unit. The freezer was in a commercial kitchen. The technician soldered up the liquid and suction piping and pressure tested the loop by putting liquid 404A into the liquid line. After a short time somebody ran out to him and said the freezer was on fire.

The tech valved it all off and rushed to the kitchen. When he arrived at the kitchen, he couldn't see any fog or vapor, but there was a kitchen employee who was clearly distressed and coughing well after being evacuated from the kitchen.

There was a bad solder joint in the liquid line. The tech repaired it, evacuated the system and put it back into service.

The affected employee gasped to the technician "That was really bad." I have to think there was an open flame somewhere.... but I don't really know.

It is an ugly situation. But other than using liquid to pressure test, I really cannot fault the technician. But we hurt somebody, and that is really bad.

And I am in a quandary. How much safety can we afford to instill? This was a $300.00 job.

Any advice, anyone?