We recently returned from a weekend away to find the heating not working, There was no hot water going to the radiators. A friend helped and we got it working by putting the 3 way switch into manual mode. A plumber attended and replaced the motor and the 3 way pipe assembly in one go and all seemed to work after he tested it. The next morning the heating came on with the hot water all fine, but after an hour or so the boiler flame stopped and the heating stopped and we can get it working again by turning the thermostat down so it clicks and then up and the boiler fires into action again. If we leave just the heating on it seems all ok, there seems to be a problem when we have both the heating and the hot water on. Is there a signal about the water reaching its temperature for the hw going astray and switching off the boiler ? It sounds like we have swapped the 3 way motor and valve for nothiner. Has the wiring gone wrong somehow ? The plumber has suggested changing the timer. Boiler is an ideal classic and is a fully pumped system.