Glow worm 24 cxi faults

[PlumbingSucks]

Hi went to look at this boiler over a week ago it was randomly showing F1 (failed to light) F4 (went out when lit) F13 (PCB connection fault) F14( htg flow >95C) when i turned up the owner said over the previous 2 days she was unable to turn it off. Anyuway checked it out and the boiler was firing for heating with the timer and room stat off with no power to the pcb external controls connection, even removed the wire and was still firing. This led me to believe PCB, glow worm tech agreed even though its usually the answer. Anyway 5 days working fine now F4 is back i'm guessing electrode or ignition lead but have read about dodgy gas valves on these! Anyone know if this is a common fault

 

[RoryD]

theres a 2ndary board that overides all. It is visible when you pop the front down, it's the little boad used to put the chb on high / low for combustion analysis with potentiometers on, that and the ribbon cables are probably the culprit.