I have a Glowworm combi that is three years old, the central heating part works fine but the hot water system trips out occasionally and has done since it was installed. Sometimes this happens when the tap is turned on but it also happens when the tap is run for some time such as when running a bath. I have always had Glowworms own recommended people look at it but, whatever they do, does not seem to work for long so if you have any ideas I would appreciate it - so that I can pass the info on to the experts!