What are the 4 pipes from the potterton flamingo 50 boiler. Two are 22mm, I assume they are for the c.h and dhw, the other two are 28mm. Are they the expansion and cold water fill from the roof tank?
I want to take the boiler out and in so doing want to maintain the cold water supply to the house.
if there are four pipes + gas supply from the boiler, then the 2 x 22mm pipes will be for the pumped central heating (flow+return) and the 2 x 28mm pipes are for gravity feed hot water (usually)