help with Chaffoteux Stirling PP Combi Boiler

[tearingmyhairout]

Our above boiler is approx 11 years old, the central heating works fine but the hot water system will not give hot or even warm water thru the tap or the shower. Even when boiler fires up the water is cold as the boiler doesnt fire up fully as well as it does on the heating system. Any suggestions would be appreciated as my husband is now tearing his hair out too.. lol Thanx

 

[LUNAT]

HI

DHW diaphragm could be split /damaged