In an earlier contribution to this discussion,
CliveM wrote:


System worked ok before, either HW only or HW & CH. Pump not touched
only the valve put in place which seems to have affected flow.

Seems very odd. Maybe the HW circuit has *always* flowed the other way when
the pump is on, and maybe it doesn't matter.

Have you wired the valve *exactly* as per the C-Plan diagram in
http://content.honeywell.com/uk/homes/systems.htm ?

The only effect of the valve (provided it is open!) should be to put a
little bit of extra restriction into the HW circuit - but not enough to
matter. [It *is* a 28mm valve, isn't it?] Have you checked that, when you
are not getting hot water, the valve is actually *open* and that the boiler
is still running for the CH? I'm trying to think of how you could have
mis-wired it to make the valve close when the CH is on, but I can't
instantly see how to do this. Anyway, it worth double-checking the wiring -
and maybe getting someone else to check it too.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.