The pump over run makes the pump circulate hot water out of the boiler for a
short time thus not making it overheat and hiss slightly like a kettle,
something like you are having. Check the manual ( if you have one ) and see
if there is a pump over run on that boiler. I think you will find it is more
likely to be the fault

"P Lavers" wrote in message
m...
"ski" wrote in message
...
depending on which boiler I would guess that the pump over run is not
operating

"P Lavers" wrote in message
m...
My boiler will heat water, but if it has been running for a while (eg
deep hot bath) then a minute or so after turning of the water there is
a clicking noise from the boiler and the pilot light goes out. If you
turn on the tap just after running a lot of hot water the water is
very hot. Seems that something is overheating and causing a saftery
mechanism to trip. However, I have had 4 visits from British Gas (I've
paid for their insurance service!!) and each time they have failed to
fix the problem. Any ideas?

Sorry for not including this info before. The make is Ocean model is
Style FF . Its an old boiler but hardly used so in fairly good nick.
Don't think the pilot is blowing out. It seems more like after the tap
is turned of the water that remains in the boiler is continuing to
get heated (although the flames are extinguished) - I can sometimes
hear what sounds like water boiling inside the boiler. Perhaps there
is a safty mechanism that cuts in due to the heating and boiling of
the remaining water? If this is what is happening what is supposed to
prevent it? What is "pump over-run"?
Thanks