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Tim S
 
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On Fri, 18 Feb 2005 10:16:46 +0000, Christian McArdle wrote:

If a combi is used with a vented cylinder, then 2 zone valves are
required, one for the heating and one for the hot water, BUT what if I
want to split the downstairs heating from the upstairs heating....


The hot water cylinder forms a zone, just like a radiator zone. Each zone
needs a 2 port valve and a thermostat, whether it be a cylinder thermostat
or programmable room stat. If you had a cylinder and 2 heating zones, you'll
need three 2 port valves. The existing pipework will determine if it is easy
to divide into upstairs and downstairs zones.

Is it best to use the honeywell cm67 wireless package!!!!!!


It is very well regarded, but a little ugly, and very pricey if you start
having multiple zones.

Christian.


I've been planning a multi zone setup for some time, due to never being
very satisfied with single zone setups.

I was considering wireless once. My conclusion:

X10: would do quite well in theory, nice DIN rail contactors available.
But not much in the way of timer-thermostats. Would end up being very
kludgy. This system is really geared to the US with some European
penetration (slow). For example, if you want to install an X10 filter at
the supply then the biggest single phase filter available is 63A, so a
100A supply would need the 3-phase 200A massive filter block. Or hope
no-one in the wrong third of households down the road decide to play with
X10 too...

Wireless: Better. But I need in some cases, 2 contactors remotely
positioned on each channel/zone. One to control a fan-convector or rad
valve and the other to contribute to a demand signal centrally. Apparantly
possible, but only 2 makers sell the receivers as separate items: Siemens
and Danfoss (and the latter do do multi-channel receivers). But as you
say, very pricey and having a bank of 100x80mm receivers commoned up at
the boiler end looks hideous.

Other systems: www.smartkontrols.co.uk produce a very nice modular system,
but I haven't the balls to ask how much it is! They don't appear to sell
parts either, preferring to offer a one-stop consult+install service.
Mucho wonga without much doubt.

So eventually, I thought, if I'm going to run light duty signal cable
everywhere for something like the smartkontrol system, why not go back to
basics and make something custom.

Essentially, a central relay box (using DIN rail for ease and neatness),
24V DIN PSU, bit of cat5 (have loads and it's fairly tough) to remote room
programmer/thermostats and wire all the relays in common for the demand
signal. Tee off to remote relays in nice tidy little boxes for
fan-convector or electric rad-valve control.

I like this solution. I have to run wires, but not heavy ones and the
system is mains-isolated and fused low so I can string the cables
anywhere I like. DIN gives neatness, wide variety of modestly priced
components and enough ease to wire a safe (mains one half, 24V other half,
proper DIN connector blocks to present the external wiring to) neat little
unit which is easy to maintain and expand.

Plus, I'm not tied to anyone proprietry set of thermostats.

Can't think of a better way. But I'm always open to more ideas.

Tim