On Thu, 04 Dec 2003 15:30:32 +0000, Roger Mills wrote:


"BigWallop" wrote in message
...

"Sammer1_uk" wrote in message
om...
Please can somebody help me?
I have a back boiler / gas fire combination ( Thorn Housewarmer e ).
The problem that I have is that I cannot get the pilot light to stay
on.
The instructions state - make sure the central heating is switched on,
hold the pilot light switch and press the ignition. Then hold the
pilot light switch until for approx 20 secs and then gradualy release.
This should keep the pilot light on. However I have tried this
numerous times but it just go's out!
I have replaced the thermocouple, but again to no success.
This problem has only just started occuring. I had the system working
yesterday but the back boiler kept going out intermittently and now it
wont come on at all. Any idea's.
I have a danfoss CH terminal. When the on switch was depressed the
whole back boiler came to life, but now it clicks but seems it doesnt
do anything else.
HELP!!

Thanks,

Darcy

It sounds very like the thermocouple, which tells the main gas valve that
the pilot flame is lit, has gone faulty. Have a web search for spare
parts
on your make and model of system, or for a supplier of a universal
thermocouple.




OP says (s)he's already replaced the thermocouple!

For the whole thing to work, the pilot has to heat the thermocouple - which,
in turn, tells the gas valve that all is well and allows the boiler to fire.

If this is not happening, it could be caused by any of the following:
* Duff thermocouple (unlikely, since this has already been replaced)
* Incorrectly connected thermocouple
* Faulty pilot flame (crud in the jet, or pilot pressure regulator set too
low)
* Thermocouple not aligned properly (so that it's not being heated properly
by the pilot flame)
* Duff gas valve

Working through that lot should hopefully find the cause, and fix it.


Agreed. Make sure the you have preperly eliminated the first four before
considering the gas valve.

On many models you can feel whether the is some 'stickiness' in the
release button. If you can feel some but it is not enough to hold the
flame on then I'd suspect the thermocouple, or not in the flame, or not
enough flame. If you feel nothing at all then a loose connection.
Note that the connection of the thermocouple to the gas valve is quite
awkward and easy to get a misconnection.

--
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
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html