geoff wrote:

In message , IMM
writes

One version of the neataheat had a plug in relay. It sounds as if this has
failed. have a look it is quite large. Check it out. Some time you can
see it arcing. If it has failed go to Maplin and buy one the same. The
makers charge more for a standard common relay you can buy anywhere..


Yes, this version - the other version is the Netaheat electronic John

If the main gas valve is opening and staying on "reliably" for a couple
of minutes, then I doubt it's the relay. If the relay contacts were on
their way out, I would expect it to either work intermittently or just
fail. It sounds to me more like the overheat stat opening and shutting
down the boiler.

IIRC the O/H stat has to be manually reset?

I agree the relay anbd gas valve are probably fine.
My guess: it's a combination of dirt on the air flow proving tubes
and/or poor contact on the switch itself. I'm guessing that as the flue
gasses warm up the air flow proving becomes marginal and this leads to a
poor contact in the diaphragm switch which makes the clicking of the
relay and the pilot gas valve.
The main gas valve 'click' has very substantial hysterisis ans is
unlikely to "thrash".

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
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