On Wed, 18 Feb 2004 20:26:00 +0000, Richard Markham wrote:

I've just had both the diverter valve and expansion tank fail on a 1997
Worcester Combi.

Having taken the old valve to bits, I found the diaphragm to be almost
crumbly...

The rubber looked like tree bark.

Any ideas what would have caused this?

6 years of being in hot water?
Perhaps you were needing to top up a lot and dissolved oxygen took a part
in the matter?

--
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