On Mon, 13 Nov 2006 04:59:44 -0800, FGoogle wrote:
Roger Mills wrote:
Each zone valve has two independent circuits - one to drive the motor to
open the valve, and one (volt-free contacts) to switch other things on once
the valve has opened. The motor circuit is driven by the programmer and room
or cylinder stat. The volt-free contacts of all valves are connected in
parallel - with a permanent live as the input and with the output connected
to the boiler and pump. That way the boiler and pump run whenever or or more
zones are calling for heat - but only the zone(s) whose valves are open get
any heat.
If you cross-connect the motor circuit to the volt-free contacts then *all*
valves will open in unison regardless of whether there's a demand in their
particular zone. This is *not* what you want!
Sorry to sound dim - but I am still confused.
Forget about thermostats for now - lets assume there are 2 x heating
circuits
These valves are N/C so no power = Closed
Zone 1 - Live - Brown and Grey Wires - When the valve opens Live
goes onto the Orange Wire
Zone 2 - Same wiring - but is off
Zone 1 puts live on the Orange wire - but as Zone 2 is off (Closed)
it doesn't get to the Grey Wire (and hence doesn't get to the brown
wire)
What am I missing?
The grey should be connected to a permanent live supply independent of
the time controls. The oranges are then connected to together and sent to
the boiler's switched live input.
[Or alternative the 2 greys and 2 oranges from both valves are connected
together to form one pair which switches the boiler form the boiler's
supply.]
Sorry to be dim
you're not it's the installation that's wrong.
-
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