refurb bathroom need advice in shutting off water?

If you turn off the main stopcock, the hot and cold water domestic feeds to the bathroom will cease - so do that and put an isolation valve in each pipe somewhere handy, so you can continue with water with the rest of the house. If you break into the central heating system, you'll lose a small quantity of water and the system will need pressurising again via the filling loop. Tip - use full bore isolator valves or you may interfere with the water flow volume. If you cut into the CH pipes, either use a stop end or full bore isolators again.

John
August 2009