While you wait for answers, we may have found some information which could help you.
Click here for Glowworm Ultimate 40ffhow can i fix my central heating. Glow-worm ultimate?
Loud clanging/Glow-worm Boiler?
fitting thermostat?
water from taps is boiling hot?
boiler will not turn off (only manually)glow-worm micron 80ff?
What can I do about a Glow-worm Flexicom 30cx fault code F11?