I have a wm 51/3 rs baxi boiler, when we turn hot water and heating on (both do not work), the boiler comes on, but after a minute or so starts to make whistling sound and then knocking, before it switches off. I was told by a plumber that it is the circulation pump, which has been replaced, but still having same problem,no heating/hot water.Can you tell me what the problem can be?
might be an air lock check the circs coming out of the boiler 1 should be hot (top ) the other should start to get warm check the circs going into the cylinder top 1 should be getting warm as the hot water circulates. if thats not getting warm then its probably an air lock
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.