On 28 Feb, 20:15, raden wrote:
In message .com, Neal
writesAll the answers have been useful, but I vote this the most useful to
me who is not quite sure of what is going on.
From this I strongly suspect it is my PCB.
After the fan starts, I am hearing a sound more like a "chonk", which
suggest from the above the pilot valvle IS opening. But then no sparks
I also think I can smell a whiff of gas in the flue.

I think I have reached the limit of my knowledge, so I have a guy
coming this afternoon (name found in littlegreenbook.co.uk- wish me
luck)
I have told him I strongly the suspect the PCB, so he has agreed to
try and bring a re[placement with him...

I take it, you've seen my site

www.cetltd.com

--
geoff

Oddly enough, I just found your site from a link on the Fool.co.uk
site

Turns out it was the air pressure switch after all. It had stuck
A knock, and it worked again....untill yesterday.
Another knock then and it worked...Until this morning
This morning: the fan has packed in. I feel like the the dutch boy
with his thumb

So, I am planning to get a new boiler (old one is clearly dying)
But in the meantime (my friendly plumber is on holiday) I need a quick
fix (2 small children....)
So Geoff, expect a call in the morning for a ("new") fan

Neal