On Sun, 21 May 2006 09:54:42 +0100, wrote
(in article . com):

Thanks again Andy, the situation does seem a little clearer to me - it
is only that involving an external party (installer) in my installation
means additional complications especially as the boiler isn't an "off
the shelf" product it seems to be easier for him to say it can't be
done etc as opposed to looking into things in a bit more detail.
Perhaps I should be finding someone who is a little more flexible...

Apologies for continually rehashing my questioning but you seem to have
the practical input that neither DPS nor Eco's could feed back to me,
you don't do callouts do you !?

If I go for H series boiler and no additonal zone valves on the
heatbank I will still need some form of diverter (either from Eco's or
an off the shelf diverter?) presumably so the flow can be directed
appropriately? The wiring for this seems straighforward and goes
directly into the mains rail of the boiler?


You could either use a diverter valve arranged so that when energised, flow
goes to the cylinder, or you could use a zone valve for the cylinder from the
same output and then a second zone valve for the CH run from the second
output normally used for an auxilliary CH pump. I went for the latter
approach because I needed to run a second heating circuit for some additional
radiators and it was much more convenient to take that from nearer the boiler
than after the normal split in the flow some metres away. I simply wire both
CH zone valves to the second output





I can specify a Heatbank without any additional zone valves ie the only
additional items on the cylinder are a circulating pump / flow switch /
backup immersion element (DHW controls) and thermostats (only item
affecting boiler behaviour). The suggested wiring diagram for this
setup appears relatively strightforward however it still outputs a
single swiched live to the boiler, however, I don't see that this is
any dfferent to standard cylinder installation and akin to the type 2
installation schematic on the MHS technical manual? The Eco manual is a
little lacking here and they describe the equivalent as the wiring for
the room stat however whether it's room stat or cylinder stat the
boiler should know that it is being called upon and fire up and then
the diverter should take care of diverting the flow appropriately?

You could do that. All that would then be needed is an additional relay run
from this output from the cylinder wiring and then used to provide contacts
for the boiler.

The boiler will provide a live to open the DHW zone valve.



AIUI the heating side would then just be a case of wiring in the low
voltage outside weather compensator and RE2132 onto the low voltage
rail?

If you use the RE2132 then that goes directly to the boiler LV rail as you
say, along with the outside sensor connection





Thanks again in advance
Robin