In article ,
Michael Pacey writes:
Hi,

I have a problem with my ancient Ideal Concord W gas boiler (says WCF
on the front). I'm pretty sure it is of the combi-boiler type.

It was working fine until recently I noticed the boiler itself is
giving off excessive heat - it is scalding to the touch. Then I noticed
that the wall above the boiler is quite sooty - not sure if this is new
or not, but I didn't notice it before. The flame seems to be burning
yellow, where I would expect clean blue, and it is lapping up in front
of the internal guard between the heat exchange and the boiler cover.
I think this is what is causing the heat coming off the boiler.

First,

**** TURN THE BOILER OFF IMMEDIATELY ****
DO NOT SWITCH IT BACK ON UNTIL IT'S FIXED

If it's sooting up the walls, it will be chucking
out carbon monoxide too, i.e. it's trying to kill you.
I presume from what you say it's not a room sealed type,
or the room seal is broken, but I can't find it on Ideal's
website so I don't know.

Is this something I can adjust myself or will I need to call in an
engineer? The bad news is I don't have the service manual for the
boiler, it came with my flat.

It will be in need of a serious cleaning out, as the heat exchanger
will be blocked with soot. It also needs thoroughly checking to
ensure the flames/fumes have not damaged anything which would not
normally be exposed to them. The flue needs checking for draft and
blockage, likewise the room ventilation.

This isn't really a task suitable for someone who's never serviced
the boiler before. It might be different if you were just asking
how to clean it whilst it was still working properly.

--
Andrew Gabriel