We're hoping to have a loft conversion done soon, in what is currently a three bed mid-terraced house - we are adding a new bedroom in the loft with en-suite shower and toilet.
Currently we have a traditional heating system with boiler in the kitchen, fed by gas pipes under the house, hot water tank upstairs and a cold water tank / condensing tank pair up in the loft.
Our initial plan was to replace this with a single combi boiler, and we got British Gas to come and do this before the loft work began. However, there was a problem with the gas supply - the current supply is not sufficient for a combi boiler, and because of the configuration of the house (with gas supply at the front and boiler at the back), British Gas said it was impossible for them to safely get enough gas through for the combi boiler. It would require routing the pipe up to the first floor, under the laminate flooring all the way to the middle of the house, then back down to the kitchen (under the bathroom) and along to the boiler at the back. They felt that this arrangement involved too many kinks, and even with 1 inch piping they couldn't guarantee that there would be sufficient gas supply for a combi boiler.
They therefore suggested that the best option was to retain a traditional system, with a slightly bigger traditional boiler, and get the loft conversion people to relocate the cold water tank into a corner of the eaves of the loft, so that it's out of the way once the new bedroom is built up there.
The builder and his plumber, however, are reluctant to go down this route, they think it's too much work to move that cold water tank, and that it would require pumps and other complications. Their plumber came to look, and thought that the risk of installing a combi boiler had been exaggerated by British Gas, and that it would be fine to route it via the first floor as suggested.
I would appreciate any independent advice on this. Is it really difficult to relocate a cold water tank into the corner while doing loft conversion work, and also what are the likely risks with using a combi boiler with a complicated multi-kink gas pipe serving it? Thanks.
