I have an old Celtic Rcs Gas Combi boiler, and the problem is that the hot water only operates in when the central heating is on, and not on the Summer (water only) setting.
It also does not work when the room thermostat is turned down - ie the pump etc has to be working for hot water.
This problem started a few months ago and we coped during the winter, but during the Summer I don't really want the radiators fully on just so that I can run a bath.
Any ideas for a solution would be greatly apprreciated. Thank you.