On Sun, 28 Aug 2005 23:27:04 +0100, Derek ^
wrote:


When iron (or any other magnetic material) is heated above a certain point,
it won't attract a magnet.

Weller soldering irons work like that. I don't know af any boilers
that do.

Curie point again .. I'm not *sure* this boiler does but the fridge
seemed to Derek? ;-)



If you remove this device at the valve end (this one unscres like a
car brake pipe fitting) there seems to be an inner bit insulated from
the outer bit (suggestiong it is electrical, a termocouple as
mentioned earlier). If it is so then I suppose I should be able to
measure the output with my DMM in and out of a flame?

Well yes, but do you know what's a good result and what's bad? DMM =
high impedance. Solenoid electromagnet = low impedance.

True, and the best way to measure voltage (high imp DMM) if I
understand it correctly, but if it was a thermocouple you would see a
change in voltage output when probe was cold / hot whereas if it was a
Curie point device I don't suppose you would?

Change the bloody thing, they are dirt cheap in comparison with the
inconvenience of having the boiler out of service.

Indeed, and part of my OP .. where is a good place to get parts for
very old Ascot / New World boiler? Luckily it's summer, they have
other forms of heating and an emesrsion for hot water it's not *that*
much of an issue at the moment.

They (I g) have no issue spending 7 quid (10 inc vat and postage /
whatever), especially if any logic, tests or experience suggests it
was a good place to start. I asked here because there's no chance of
getting something rolling till Tuesday and I thought I could try any
tests suggested before then?

Let me try a different way ... is there way of testing the flame
failure device (if that's the right name for it) on an older (non
electric / electronic) boiler please? NW CH502.

All the best ..

T i m