No hot water - Valiant Ecotec 430 Plus boiler

[Tomc32499034]

We moved into house a year ago, have a Valiant Ecotec 430 plus boiler, and the tank shown in picture next to it. Everything been fine but no hot water suddenly yesterday. Had a look and the pressure in the red tank had fallen to 0.85 so repressurised it up to 1.25 but stil no hot water. Initally pressing the button to adjust hot water temperature on boiler gave a message "Cylinder charging off" but that has gone away now. Going into the menu and selecting "Live information" (as i found in manual) it says "No heat demmand controller" - but ive never looked at the boiler before so don't know if that was there before or not. The other button at the bottom when you press it says "shutdown" and seems to restart the boiler, where upon there is a few seconds of activity but then nothing. Obviously have tried pressing the boost button on our controller which usually do if need hot water when run out. Also usually it comes on, on a timer a couple times a day. If anyone has any ideas what i need to do to fix it, would be very grateful. Thanks

 

[terryplumb]

Show us pics of your hot water cylinder and any valves and pipework around it , plus your controller.