In article ,
Richard writes:
Thanks for your advice
Man acme today, fitted new fuse and after 30 mins spooted micro leak
in seal where flue attached to boiler. This is the black rubber
gasket. It seems it is sealed by just silicon from a gun. If it lets

I can't picture a black gasket in the flue path.
Was this the burner gasket -- the large rectangular
gasket on top of the rectangular heat exchanger box?
A leak at this point would be very hot, whereas a
leak in the flue would be much less so.

I did replace the burner gasket on mine during servicing as
a) it was impossible to get it off in less than about
10 pieces because it had been glued on, and
b) it had hairline cracks through at several of the
mounting holes (although I couldn't actually see any
sign of leaking there).
I didn't silicone in the replacement gasket as the instructions
don't say this is necessary. I did check it again a week later
to make sure it still looked OK with no sign of leaks/cracks.
I bought a couple of them -- can't remember the price but
it was under a tenner each.

water out, then it can cause a build up of steam in the cabinet thus
causing thermal cut out.

Hum, did it look like it had corroded anything in the
boiler (the steam is acidic)? The thermal trip probably
caught it before it had a chance to do so.

So all working again. Must say next time its serviced I will get them
to check the silicon seal.

If it is the burner gasket, this is supposed to be open at
each service anyway, to clean the burner and surrounding
area.

--
Andrew Gabriel