While you wait for answers, we may have found some information which could help you.
Click here for Combi Water Runswater from taps is boiling hot?
Intermittent boilet fails to fire on heating?
Glow-worm micron 60ff boiler niosy ?
how can i fix my central heating. Glow-worm ultimate?
how to find a fault?
Loud clanging/Glow-worm Boiler?