In an earlier contribution to this discussion,
Set Square wrote:

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

On Sun, 11 Apr 2004 14:54:13 +0100, "Set Square"
wrote:


Matthew

Check the wiring in your junction box. When hot water only is
switched on, pins 1 and 6 in the junction box should be live. When
you turn the cylinder stat up to a high temperature, pin 8 should be
live (and pin 7 not live). When you turn the cylstat down to a low
temperature, pin 8 should cease to be live and pin 7 should become
live instead.

The boiler and pump (or just the boiler if the pump is connected via
an over-run stat on the boiler) should be connected to pin 8 - so
the boiler should fire when the cylstat is turned up.

Check these things, and let us know the score.
--
Cheers,
Set Square
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Thanks for the help - not bad support for an Easter Sunday!
OK,

If I ask for HW only, pins 6,7,8 and 9 of the Danfoss wiring box are
live! This doesn't sound right!

If I drop the stat temp, then 8 and 9 go off.

The boiler is on pin 9, which in turn is linked to pin 8 (as per the
installation sheet) - which seems OK.

Pin 7 is the "HW off" from the stat, I think

Hope this is starting to make sense to someone!

I was referring to the pin (connection) numbers in the 10-way
junction box shown under Y-plan in
http://content.honeywell.com/uk/homes/systems.htm

It sounds like you have a different wiring scheme if the boiler is on
9! Do you have a reference to a diagram which covers your setup? [On
the Honeywell diagram shown in my reference, 9 and 10 are not used!]

That aside, if - as you say - 8 and 9 are live when calling for HW
only, and the boiler is on 9, I'm at a loss to know why the boiler
isn't coming on and heating the water.

If your wiring scheme is like the Danfos diagram referenced by Lurch - with
a 12-way junction box - then the following should apply:

With HW only selected, Pin 3 of the programmer should be live and this
should be connected to Pin 6 in the juction box, which should also be live.
When the cylstat is turned to high, pins 8/9/10 of the junction box should
be live and pin 7 should not be live. When the stat is turned down, 8/9/10
should no longer be live, but 7 should now be live. When 8/9/10 are live,
the boiler and pump should operate.

Does this make sense? If this matches your setup, please let us know what
*really* happens.

--
Cheers,
Set Square
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Please reply to newsgroup. Reply address is Black Hole!