While you wait for answers, we may have found some information which could help you.
Click here for Glowworm Central Heating Systemboiler will not turn off (only manually)glow-worm micron 80ff?
radiators hot when water turned on?
Glow-worm 30cxl?
how to find a fault?
What can I do about a Glow-worm Flexicom 30cx fault code F11?
Intermittent boilet fails to fire on heating?