i have a new oil condenser combi boiler and wish to add 2 extra rads, do i drain the system , if so how do i go about it, the boiler is outside, any advise would be very much appreciated,i am an x plumber retired now, and only tackled gravity fed systems, not mains pressure like this one, any help would be great thanks…..

I have hard well water. My copper tubing is leaking thru pinholes in about eight places now (all repaired, but the latest is in the ceiling above the kitchen!! Grrr!)
I’ll be installing a good filter, but it seems like the smart thing to do is install Pex tubing.

So where can I learn to do it right?

I’m not a plumber, but I don’t want to learn by trial and error!

I figure I’ll do the job, then sell the tools.