We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember chris French
saying something like:

Cehck with the pipe you use over the connection to the boiler. when I
used Hep20 they said to use 1m of copper first - IIRC Speeedfit has the
same sort of stipulation.

They all do.
I visited a boiler which had been installed by a cowboy who'd run the
Qualpex pipes right up to the boiler - amazing it lasted so long, but
even Qualpex couldn't stand it for more than a few months.