I'm having a boiler replaced and have chosen a combi boiler. One of the benefits is mains water pressure hot and cold water where previously I had low pressure coming from a tank. The boiler is in place and the hot water is plumbed and the pressure is fine, but putting the mains to the cold taps in the bathroom is a problem.
I'm the top flat of three storeys (ground floor; first floor; my floor) and there is a large water tank in the loft which serves the block. Due to access restrictions and the way the place was built the pipes go up in to the loft and then down in to the bathroom. We are going to do the same with a new mains pipe to the bathroom. However, we can't just drop a new mains pipe down in to the bathroom unless we rip the bathroom out because the pipes go to the mixer behind the tiling and we can't see a way to drop a new pipe down. It's a bathroom that is less than 5 years old so I'm loathe to start ripping it apart.
Could we cut the tank pipe and put the mains through it? This would give me and any other flats mains pressure for our cold taps in the bathrooms. Is there something that could go wrong with this?