boiler codes

Hi, just after the mains stopcock under my kitchen sink I have a tee, one pipe to drinkable water+washing machine and the other to the loft cisterns (talking about an open vented pumped S-plan system, standard here in UK, aka "hydronic heating system" in USA). I was wondering whether it is safe...

I am adding radiators to my 2-pipe central heating (UK). The whole piping is copper 22mm and microbore, and I'm extending it with 15mm pex barrier pipe graded for central heating. I know that the first bit of pipes connected to the boiler must be copper, which is the case. However, I couldn't...

I recently replaced a boiler feed backflow preventer. There was a ball valve upstream of it but nothing to isolate it from the boiler system except the boiler feed pressure regulator. I thought that if the boiler is above the set pressure for the regulator, then the regulator valve should be...