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


The W-B Greenstar 29HE installation manual shows a "Y-S wiring module"
with a connection called "DV" or "Boiler/pump demand" but doesn't
explain what this does. Am I right in thinking that it's an input to
enable the boiler to fire only when the pump is running?

The FAQ mentions outside weather compensation but I can't find any
details on the web, can anyone enlighten me about this?

Can anyone suggest a cheap basic 3 channel programmer?



Don't know for sure, but could the Y-S wiring module be a junction box where
all the electrics are connected when the boiler is part of a Y-Plan or
S-Plan heating system?
[See http://content.honeywell.com/uk/homes/systems.htm for plan definitions]

Again, I don't know what DV stands for but, if it's in an external wiring
centre, it sounds like the point where the boiler and pump are connected.
Alternatively, if it's on the boiler itself, it could be the connection
which allows the boiler to control the pump (not the other way round!) by
means of an over-run stat.

Do you have a URL for an on-line version of the manual? I had a quick look
on the W-B site, but couldn't find any manuals.

Thanks for the honeywell link, v.useful. DV is on the boiler and
connects to "Boiler/pump demand" in the wiring centre (the manual is at:
http://tinyurl.com/3slyp - 1.4Mb).

--
Dave S
(The return email address is a dummy)