D
diamondgas
I get the reason they require this to be done. I know how a 2 port zone valve works, but I wonder who actually does this? I been in hundreds of houses fitted loads of new and replacement systems and never seen it done.
What happens if someone wants a boiler replacement but just had new carpet and decorating and dont want all the boards up to fit an extra flow and return?
Never mind two zones there are plenty changeovers I come across without the required TRV's or temp control, haven't been flushed and the condensates dribble down the outside wall!!! Who polices building regs anyhoo's?