In message , Ed Sirett
writes

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

If the APS is knackered, it will not bring on the fan

It needs a good short circuit between the normally closed and common on
the APS to allow the fan to work

I'm not sure that your "clearly dying" diagnosis is necessarily anywhere
close to the mark

I'm not sure of the price of an APS, but added to £75 ++ for a fan AND
pcb would be far less than the cost of replacing the boiler at £1500 or
more


It's not replacing the boiler that costs. It's upgrading the heating
system to comply with Part L

Hence the £1500+ price tag ...


--
geoff