Glow Worm 30cxi fault code F12

Discussion in 'Plumbers' Talk' started by unphased, May 18, 2019.

  1. unphased

    unphased Screwfix Select

    Good morning, my boiler packed up last night so I'm trying to fix it. Done some research around fault code F12 and it seems to relate to the PCB and wiring between that and the user interface. The boiler is now 12 years old and its had a new diverter valve two years back and new safety pressure valve about six months ago so its performed well. Any advice appreciated.
     
  2. Mike83

    Mike83 Well-Known Member

    Is the fault intermittent?
    Does the boiler reset and run for a period of time?
    You could check the wiring harness’ inside.
     
  3. unphased

    unphased Screwfix Select

    Hi Mike. No its not intermittent. I've just done a visual check of all the connectors around the PCB and pushed them home again. No sign of any broken wires. When I switch the boiler on I hear the fans start and after about 5-10seconds the F12 shows with red flashing LED. The boiler won't fire up it just stays in that state.
     
  4. unphased

    unphased Screwfix Select

    I'm going to take a punt and replace the PCB. £208.00 incl. VAT :eek:. If that doesn't cure it, new boiler me thinks. :(
     
  5. The Teach

    The Teach Well-Known Member

  6. Mike83

    Mike83 Well-Known Member

    Had similar fault on this boiler and it was the main pcb.
     
  7. unphased

    unphased Screwfix Select

    It was the PCB. Replaced it and now all working okay again. :)
     

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