A few days ago, our boiler and local pipes began to vibrate when CH started up. Running a hot tap (to override CH) caused it to stop immediately. Suspected faulty CH pump maybe. Plumber took a look, that seemed to be the case and we ordered up a replacement pump. No sooner had he gone than we had no hot water at the taps. I turned off the hot water slider at the controller, set CH to come on, and the CH started to work perfectly - no noise from pump/boiler, boiler firing up, all rads warming up. It has been like that ever since. However, DHW still does not work - I can get hot taps to run fine, but cold water only, so presumably the hot water pump and flow control are working ok BUT, the boiler does not fire up for hot water. Any thoughts on the fault would be appreciated - plumber not sure though he has not been back yet ... was going to come to fit replacement pump but it looks like it could be something else. Could it be a thermostat fault maybe? Help much appreciated, thank you
