About 4 years ago I cam across a job that caught my eye!! I had a call from a guy with a leak and when I turned up water was pouring out the front of a CWE valve handle I had a chat with the owner and the system was only a week old so I went and looked further into it. The plumber and i use the term very loosely had plumbed the CWE drain back into the cold feed before the PLV so the CWE was recieving higher pressure at the drain than at the inlet but that wasnt all the trp drain went out through the wall and dropped down 2 stories in a garden hose and to top it off there was no tempering valve on the system.
The owner reported this to the board and I was asked to testify about the installation and the plumber once again used very loosely had only had a limited licence for a week and was working alone glad to see abusers of the system punished but this could have been very bad!!

Linkback: https://forum.plumbers.nz/solar-heating-and-heat-pumps/9/bad-solar-job/1094/