On Wed, 31 Mar 2004 18:00:26 +0100, "IMM" wrote:




That is the point, it is cheap to install, with no zone valves, etc.

Zone valves are hardly expensive, are they?

They are.

In the context of a complete installation not at all.

You will need three with a normal boiler. Then there is the
fittings and pipe and pressure by-pass valve, etc. The Junior comes
complete with one inside.

Which will be reflected in the cost. It isn't "free".





Read what I wrote above. It is clear.

With your writings, clarity is not a description that I would use all
that much.




You can put them both together One,or both, can go at the back of the
airing cupboard, still releasing tons of space by the redundant cylinder.

... needing a gas supply to be run there.....

Great thing eh!

It all adds to the cost.



The two combi setup, has few disadvantages
and the only one you picked up on
is the increased cost of servicing, which is not
a great amount.

Only double, but that's not a lot, I suppose.

Nonsense again. No zone valves of any sort would be in the system, either
externally or in the combi's. This make the system as whole far more
reliable, with built-in redundancy.

What you are describing does not equate to redundancy. You are
talking about a boiler per zone for heating and hot water. Since
you have described these as being autonomous systems because of lack
of zone valves, it is not redundant in the least.

Redundancy would happen if both boilers were plumbed together in such
a way that one would take over from the other in the event of failure
or both run at part load with the ability to cover for the other in
the event of failure. This would require an altogether more complex
form of controls and components to implement.

Having HW and heating available in only part of the house is not
redundancy, it's impaired service - not the same thing at all..





You clear haven't a clue.

I clearly do

Another know-it-all.

If you look at your typical posting style, evident in this case, there
is only ever one way, as far as you are concerned and everything and
everybody else is wrong.

I grew out of that attitude before my tenth birthday,


Read what I wrote again.
Read about the system and its advantages in:

- space saving,

compared to what? Certainly not one boiler.

- redundancy,

Definitely not.

- high flowrates,

It depends on what you mean by high.

- Natural zoning,

which could more easily be achieved with zone valves.

- hardly any electrical control work (running a wire to a programmers/stat
and power to each,

Marginal difference to a zoned installation.


- simple no brainer installation,

at a cost in terms of implementation of services etc.

- minimal components used.
- etc.

I'm not sure what the etc. is. It's one thing having multiple
boilers in a commercial installation, correctly implemented; of little
benefit in a domestic one.


Now read it again and come back with sensible questions.

I don't have any questions.



This method is catching on and most makers now, will give a diagram on how
to combine the outlets of the boilers. Worcester-Bosch will give one.

I bet they will.




..andy

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