Plumbing Questions? Ask a Plumber for Answers ASAP
Hello, to clarify, is it the hot water from the tap that won't stay at a consistent temperature?
1. How old is the boiler?2. What is the water hardness in your area?
Then your plumber's theory is plausible, assuming that he means that the DHW heat exchanger is scaled up, and assuming that you don't have any anti-scale measures in place.Why do you want to order the part - are you planning to do the work yourself?
You're welcome.Is the maintenance plumber who visited you a Gas Safe registered engineer?