On Tue, 14 Feb 2006 08:03:13 -0800, bedazzled wrote:

Many thanks. I have now found out that it is a defective diaphram
which under water pressure pushes out a pin to operate a switch which
then fires up the water.

That's pretty much the most common arrangement.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://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
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html