We may have found other answers which could help you.
Click here for Glow Saver HeatingI have a 30cx glowwarm that is showing F4 as fault.I have no hot water?
BMU error code?
GS 24i junior boiler timer broken?
Glow worm flexicom 30cx auto air vent - how do I replace?
fitting thermostat?
Central heating not working?