On Sun, 11 Apr 2004 15:56:17 GMT, in uk.d-i-y
(Matthew Humphreys) strung together this:

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.

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!

I think from what you say pins 8+9 are the boiler and pump.

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

That sounds right.

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 think this might help. http://tinyurl.com/3fyca I'm assuming the
wiring you have is as this diagram is, if it's different then what I
said could be totally wrong.
If I were you I would check the wiring at the clock, stat etc and
ensure it is all right.
--

SJW
A.C.S. Ltd.