Thanks for all your advice, I thought I was getting railroaded by BG into the pressurised system. The BG engineer claimed, or hinted, that my current system could not be replaced. He refused to consider replacing like for like or to consider any improvements or alternatives based on the boiler...
The hatch is 740x840, however I think the challenge would be getting a new tank past the roof trusses. Looked in more detail at the loft tanks, they are both looking fine, a bit of sagging in the sides on the CW, both are open topped and no insect kit as you would expect
The main driver for change was to take the 45 year old cold water and heating header tanks out of the system also the similar aged HW tank. Changing / replacing the tanks, due to loft hatch sizes, will be a huge challenge. Do they have to be so large? I estimate the cold water tank at 160 litres
I think I already know the answer to this question but I’ll post it anyway. Would anyone consider changing an existing 45 year old open vented heating and HW system to pressurised? The existing system is, in the main, hidden in walls or under flooring. The heating system is microbore and the...