Hi,

some may recall my posting about a C/H problem where my Jaguar boiler
cut out intermittently, and never when an engineer was looking at it.

On 5 occasions over the 6 months, 3 different heating engineers looked
at it, and none could/would diagnose the cause.

It was definitely an overheating problem, with F1 error code meaning the
thermostat next to the heat exchanger needed resetting, or F3 error code
simply meaning an overheat of something, and where it would fire up
without attention, once the temp had fallen.

I discussed faulty pump with each of them, and none were sure saying
that they didnt want to spend my money when it could be something else.

Over time, and listening to them, and to the boiler, (including a
screwdriver to the pump and my ear), I recognised that the sequence was:

thermostat demands heat, boiler fires up, pump runs for a period from a
few seconds, to a few hours, pump stops, temp rises, thermostat cuts the
gas.

I was therefore reasonably certain that either the pump was faulty, or
something was stopping power getting to the pump.

Eventually, I insisted that one of the engineers fitted a new pump to
test my theory, and it seems to have worked a treat.

What a job I had to get one of them to do it! I had to insist that it be
done, and that I wouldn't be upset if it didnt work.

I guess that I am probably luck to have such honest engineers, who dont
want to spend my money unnecessarily, but it has been a frustrating 6
months with sporadic, or no heat.

Why am I writing this?? Well, I suppose it is to say that there seems to
be no real way of diagnosing the cause of a problem with certainty, and
it may be necessary to spend money on a number of possible cures in
order of reasonableness, in order to exclude particular things.

--
Richard Faulkner