I think that you have been rather too trusting of that fellow.
To me he was unable to diagnose the fault and knew that the diaphragm was not likely to be the problem.
All the evidence points to him ignoring your telephone calls from your known knumber.
As far as I can see, your system is fine now that you have reduced the DHW flow rate.
Tony
To me he was unable to diagnose the fault and knew that the diaphragm was not likely to be the problem.
All the evidence points to him ignoring your telephone calls from your known knumber.
As far as I can see, your system is fine now that you have reduced the DHW flow rate.
Tony