Baxi 105 HE

[ginger]

Happy new year to all. and i guess back to business as usual.

i'd be grateful for any advice on this one, here goes......

the outlaws/inlaws have a baxi 105HE (with water preheat) and it has given out on them, So a call out to their usual plumber (Corgi installer but not fault finder) to do the repairs. so now they have had a new expansion tank fitted after it was found to be leaking. also had a new PCB fitted and various sensors checked. but after all this the plumber has left scratching his head.

now the boiler is flashing no errors and all sounds well (pump starts circin' and gas valve opens, also fan starts up) the problem is the thing will not light.

it doesn't ignite even though everything seems in order.

can anyone give me any obvious problems that come up on this model.

my first thought is the air flow switch but you guys will know more than i do i'm sure

thanks in advance

[rusm]

if there is no spark it is worth checking air pressure switch.