if on hot water only do you get a click when you run the tap?
Have tried 2 taps at once, no different. If thr C/H is actually running, ie heating rads, the water runs hot.
It has been intermittent for a while.
OK thanks, is it a big job?
Thanks very much.
The engineer did a temporary repair, and is coming to fit the new diaphragm on Thursday, cost £100.
£100 total that is.