"John" wrote in message ...
"Alan" wrote in message
m...
My 10-year old boiler (conventional, open flue) has started smelling
of gas when it fires up (and recently set my CO detector off).

Make and model please?

The flue and ventillation are all fine. I've checked the input and burner
pressures and gas rate - all spot on.

On what basis do you state that the flue and the ventilation are all fine?


The flames don't look too good - very yellow and look too big. All the
burners etc. have been properly serviced recently and this hasn't
fixed the problem.

who carried out the service and what did it cover?



regards,
Alan

Well, the original technician who serviced the boiler, then condemed it
reckoned it needed a new burner assembly - "but the boiler was obsolete
so probably wasn't worth repairing". I tried to get some other opinions
- one plumber never returned my call, another said he could fit me in
3 days later, but he never turned up...

In the meantime, I found the service manual on-line, made myself a
manometer with a bit of plastic tube, dis-assembled the boiler to
check the lint arrestor and injector (all fine), did some smoke
tests with some smoldering kitchen roll and found the
heat exchanger still quite sooted (I know I said it was clear, but
I am no expert and the bloke who cleaned it a few days before was...)

Spent a while properly cleaning the heat exchanger, then tested for
leaks and inlet & burner pressure with the manometer and rechecked
gas usage - all seemed fine, the yellow flames have gone, the CO
detector stays off and the bad smell gone. So I peeled the
"Immediately Dangerous" sticker of my boiler.

So if you hear of a large explosion in the Manchester area...

regards,
Alan