Thanks, bought and fitted diaphram kit /mini seal. Upon restarting I'm getting the pump kicking in but the flame not starting or then it starts and then knocks off again but the pump continues, ie cold water. No fault leds are flashing. I presume it's something to do with the sensors but can't...
Following previous leak, fitted new Diverter Valve Assembly and fine for just over a week, now a leak again from the same place, where the grub screws secure the DHW Pressure Differential Valve to it.
Have read a lot of similar items on this site but none where a new one has been fitted...