What does " F9 " imply on a light worm combi boiler?
Answers: First of all what model glowworm is it. on the cxi F9 usually indicates a hose down pressure sensor fault. Theres a reset competent over heat stat top vanished hand side of the grill exchanger (a little red switch). press this in and consequently try it..remember to turn off adjectives electrics to the boiler before u do this. If this keep happening nearby is a problem that needs to be investigated.
If your pressure indicator is below 0.5 ,top up water pressure to 1.0. If this is not the shortcoming switch boiler off at D supply (not on/off switch on boiler) for 10 seconds afterwards switch back on, this may oblige.