I don't know the first thing about boilers which is why I am on this forum - I don't know what a diaphragm is or why it should mean I have hot water in the bathroom sink but not in the shower. Any further information would be really helpful. Thanks.
Thanks for the responses - and yes I will get a new engineer
This sounds like something we haven't tried - so thank you. I will ask my engineer about that. How much should replacing something like that cost?
I have a Vaillant Eco tec 28 which was fitted just under 3 years ago. After working fine until a couple of months ago The hot water in my shower runs fine for 3-4 minutes then runs cold. the hot water returns after about 30 seconds or so but a few minutes later it happens again. I had an...