DIY Doctor UK DIY Forums

Hi, can anyone help me. I have a glow worm swiftflow 100 combi boiler and I cannot get hot water unless I have the heating on, also when the hot water is running I have to keep it to not much more than a trickle or it begins to run cold.
Any help with this would be much appreciated.
Thanks

Gas pressures or diverter fault, possibly split or stretched diaphragm. When the hot tap is running, hold the CH flow - does it get hot ?

htg

Also possible scale build up in HEX