While you wait for answers, we may have found some information which could help you.
Click here for Flow Heating WaterGlow.worm ultracom 38 cxi showing f25 faultcode?
Clearing a blockage from a heat exchanger?
Glow-worm 40B system top-up and inhibitor issue?
central heating wont turn off?
how can l fix my gas control valve?
Is it normal that the flame is burning all the time?