"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
ARWadsworth wrote:


The Honeywell W plan download from here

http://www.honeywelluk.com/article.aspx?ai=sysplansdl

states that "the programmer should be one which does not allow
heating to be selected without hot water". (register yourself to get
the downloads, Honeywell will not know that you are not a company) or
I can email you the download if you want.

Yes, you're right - I stand corrected! With the system as specified, the
valve *only* gets energised, and the flow diverted to the CH, once the HW
stat is satisfied - so you *have* to have the HW on unless you turn the
stat down.

[I was sure that I previously registered, but it didn't think so, so I've
(re-)registered and can now see the documents.]


http://content.honeywell.com/uk/homes/Schemes/w1.jpg

is the missing picture for the W plan diagam

You are correct in that you can turn the cylinder stat down. That
would be a PITA or impossible for most people (do you know many jobs
I do where the customer does not know where the fuse box/CU is?)

About 4 years ago (Christmas time see PS) I believe that you made a
post about W plans and using the HW off from the programmer to allow
CH only. I cannot find the post on Google. I remember not trying it
in the end (although I agreed with your idea at the time) as I worked
out that the boiler would fire up constantly.

Interesting that you should say that. I have no recollection of suggesting
that in the past (but that's no guarantee that I didn't!) BUT I was about
to suggest just that before reading your paragraph above - and still am!

I reckon that if you connect the programmer's HW-OFF to terminal (5) in
the junction box, that would have the desired effect. The valve would be
energised all the time but the boiler would only fire when either the CH
demand was unsatisfied, or the HW demand was *satisfied*. The latter is
unlikely, since the water is not being heated - but I suppose it *could*
cause a problem if you turned the HW off when you already had a tank of
hot water. It would work best if HW were either permanently ON or
permanently OFF at the programmer.

One small problem. Terminal 5 in wiring centre is linked to term 2 of the
cylinder stat. A HW off with the stat not calling for heat will fire the
boiler.


I also found this for Y plans (the wiring diagram is actually
incorrect, see if you can spot it?)

http://content.honeywell.com/UK/homes/files/pag109.pdf


I presume that you're referring to the fact that HW-OFF is missing on the
timer (even though it's there on the control schematic)? Incidentally,
that particular diagram is *not* the same as the one you can download from
http://www.honeywelluk.com/article.aspx?ai=sysplansdl once you've
registered - which is the old one which we all know and love.

Correct. That was quick.


and this for S plans

http://content.honeywell.com/UK/homes/files/pag110.pdf

Are they any better as to the types of links you want to replace
missing ones for the Wiki?


Probable - although the downloadable 'traditional'ones are even better for
imparting a basic understanding - but maybe that's because those are the
ones I was brought up on? If they are going to be referenced from the
Wiki, they'd have to be put somewhere where you can see them without
needing to register - which would very likely violate Honeywell's
copyright and terms of use - which I blithely ticked to accept without
reading!

I will keep looking for others then.

Adam