Hello, I am having a new shower installed which requires a high pressure water supply. We have 3 bathrooms (2 baths & 1 shower) and currently have a potterton netaheat profile boiler with a standard size hot water tank (which doesnt completely fill the 2 baths together). My builder has suggested I have a megaflow system installed and says his nephew could do the job for £8,000 which would include new boiler, double the standard size cylinder tank and megaflow system. He would also move the cylinder (currently located in the hall airing cupboard) to the loft. Is it necessary to have a new boiler and cylinder - I wondered if I could get a pump for about £500 and have that installed instead? The cost my builder proposed staggered me, but I know very little about plumbing and heating.