Got a bit of a weird problem with our boiler. It's a Glow-Worm Economy
Plus EP40B (non-combi) with a pilot that should be on all the time.
If the external temperature is above about 0, it's usually OK. However,
in the recent cold snap, and after the boiler has been running for a
while (so is hot), and about 2 mins after the main burner turns off, I
can hear "clunk" and the pilot light goes out.
I had the thermocouple replaced recently, so I think that's OK. (I can
always re-light the pilot easily when the boiler is cold, and it will
stay on until the end of the next period when the main burner is used).
It seems to be something to do with the difference with the outside air
and the boiler temps.
One thing I have noticed is that only the very tip (2mm or so) of the
thermocouple is red. Could a draught caused by the temperature
difference be "pulling" the flame away from the thermocouple
sufficiently to turn it off? Is the thermocouple in slightly the wrong
position? Or could the flame not be strong enough (is there any way to
Ideally I'd like to solve it myself, but understand that most things
should be done by the pros.