"Neil Jones" wrote in message
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"IMM" wrote in message
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"Neil Jones" wrote in message
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"IMM" wrote in message
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A real cheap solutions is to create a
manifold and have all the rads
flows off this. Each rad has a 2-port
zone valve (cheap at £21 at BES) and
each rad has an electronic wall stat.

This only goes half way, though. With
a simple wall stat I can't say
that I want my bedroom at 18C between
10pm and 11pm, and 20C between 6am
and 8am, and that I don't care what happens
in between as long as it
doesn't go below 5C.

Then replace the simple wall stat with a wall stat/programmer. Some
of
these are now quite cheap and well specced. So, one single channel
timer
for the DHW and only wall stat/programmers. But I would have a single
channel timer on the CH to make sure all the CH off, a master
controller.
This could be programmed to be on for a few hours a day when on hols.
For
frost protection, you could have a switch that only allows the hall
stat/programmer to operate and all zone valves are powered full open
bypassing the room stat/programmers.

This is a good, relatively simple, and very effective solution for a
new
installation, using ready made off-the-shelf parts, that any heating
engineer can understand, but may be disruptive to re-divert the
existing
pipes.



OK, so I've got £23 for the zone valve and £30
for the programmable stat, per room.

They are available for far less than that.

Plus wiring to supply each stat, and replumbing, and
redecorating. I don't think your suggested system is realistic as a
retrofit, in my situation, at least.

That is what I pointed out. If renovating then this is a good solution.

All of a sudden, Andy's suggested £100 per HR80 looks rather more
reasonable (purchase of shares in Duracell notwithstanding)...