On Thu, 09 Feb 2006 01:25:42 -0800, harry wrote:

I have read
(http://www.gasman.fsbusiness.co.uk/f...ed_systems.htm) that on a
fully pumped open vented system the cylinder return must be the last
conection before the boiler. Why is this? I have this system but the
cylinder return is 3 radiators with trv's into the heating return side.
Is this going to work or should I extend the return back to the boiler?
(which will mean taking the floors up again). Or is there an easier way
around it?

Thanks for any help


There is a possibility that if some of the radiators return before the
cylinder return _and_ some after the cylinder a problem will occur.
When doing HW only then some of the return water will flow backwards
through the 'upstream' rads to point where all the radiators have a
common connection on the flow side. Then through the remaining rads to
join the 'downstream' return connection. This will cause the house to heat
when not required. A confirmation that this is happening is that some
radiators will get warm starting from the side that's normally cooler.



--
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