On Mon, 27 Nov 2006 08:59:15 -0800, davem wrote:

the whole system is working 3 port valve does the right thing when
told, thermostat on water tank does switch on and off if turned
manualy, pump is working, heating to rads works but....no hot water.

Hot water does flow into the tank and out of return pipe. both pipes
get hot, too hot to hold for very long but water in tank not heating

There is valve on the return pipe, currently this is fully open, should
this be closed to restrict the flow ? or is there some other problem.

Any advice appreciated?

The valve could be broken in the mostly closed position (especially if it
a gate valve).

To hot to hold for very long (about 50-55C) the flow should be
scarcely touchable say around 70C and the return at least as hot as it is
now. So may be boiler thermostat nees to go higher.

Are there any dripping HW taps?






--
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
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards