"Set Square" wrote in message
...
In an earlier contribution to this discussion,
xena wrote:


Here's a pic of the system:
http://www.ukosborne.co.uk/images/system.jpg

Is the zone valve likely to be the silver box at the bottom of the pic
marked "Downstairs heating"?

Yes - that's the zone valve.

[The other silver one is for the upstairs heating and the white one for
the
hot water. You have an S-Plan-Plus system. The downstairs zone valve is
driven - or should be! - by the downstairs stat, the upstairs valve by the
upstairs stat, and the HW zone valve by the tank stat. When any
combination
of zone valves are open, the secondary contacts inside the valves switch
on
the boiler and pump].

Does the upstairs stat work ok? Is it the same type of stat? If so, see
how
that is wired and replicate it for the downstairs setup.

I'm home alone til hubby comes home later, but we can try listening
for sounds then.


Well worth doing - I think we may be getting somewhere.

The wire from the silver box at the bottom of the pic marked
"Downstairs heating" is the first black wire in
http://www.ukosborne.co.uk/images/wiring.jpg
and has five colours coming out of it. If I'm going in the right
direction, let me know and I'll see exactly where the wires go.

Definitely! I can't see where they go from the picture - you will need to
lift the wires to see where the ends go.

Can you also post the make and model of the zone valve. Hopefully we can
find an online wiring diagram for it. If it's like the one in
http://content.honeywell.com/uk/homes/systems.htm the motor is connected
between brown and blue, and the grey and orange wires switch the boiler
and
pump on. In this case, the question is: does one of the wires from your
stat
connect to the zone valve's brown wire? If so, which one?

Hi Set Square

Think we're sorted now - see other post. I'm gonna get the Drayton Digistat
2, and all will be well.

Thanks for explaining the heating system - I'm gonna take a print of the
S-Plan-Plus system and leave it for the next owners!!

You're brilliant, thank you so much!