On Mon, 12 Apr 2004 11:20:09 +0100, "Set Square"
wrote:

In an earlier contribution to this discussion,
Matthew Humphreys wrote:


Which of the connections to the valve should be live for just the hw
to be heated?


Essentially none - but the wire which is connected to Pin 8 in the junction
box will be live because Pin 8 is powered from elsewhere. Some of the others
may glow dimly on your screwdriver because they're connected via the motor
windings etc.

The valve is least active in the Hot Water only position. It sits at its
"home" (spring return) position, where it directs water only to the heating
coil in the hot water cylinder. In this position, the actuator plays no part
in switching the boiler and pump - they are switched by the cylinder stat.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!


OK, perhaps we're getting somewhere!

I've had all the wiring double checked by a friend - we are confident
it is OK.

When I ask the system for hw on pins 6,7 amd 8 are live.
When the water is hot, 7 and 8 are live (7 is HW off, 8 is feed to the
boiler as you explained above.

This now seems to be logical!

One thought I had was that as the system is expecting a Danfoss
Randall 3 way valve, which has the CH/HW - A/B ports the other way
round (doesn't it?) and I have a Honeywell 3 port valve, is the
controller trying to ask the port to do the "wrong thing"?

If this is utter tripe, please tell me, I'm a mechanical engineer not
an electrical /heating engineer!

Is there any way to manual operate the valve to the "rest"/ HW only
position to see of the valve is playing ball.

What else can I do to check the valve is OK?

Any other ideas anyone?

Thanks for all the help over the last few days,



Matthew