I have a Baxi 105e combi. Problem was I was getting no gas flow to the burners. checked the pressure switch which is working fine.generating a spark ok & fan switching on OK. Local engineer said it was the PCB card. SO he changed it and now we get another fault and he's scratching his head!!
New fault is that on demand form either HW or CH the burner lights up for approx 1 second then goes out! the system then retries three times with exactly the same outcome then faults under the 30oC led (flame). its november and the house is freezing!! help will be appreciated.

andyroo, November 2006

i had the same problem.

what i did was, under the gas valve there is a little black nut/screw which seems to adjust the pressure in the heat exchange chamber. try turning it either way until it stays lit.

Jedi Dave, December 2006

try changeing the thurmal coupling

phil, November 2006