Just bought the above wireless thermostat and a separate programmer to control my combi. Both are 7-day ones. The reason for this setup is that we do know exactly where we want to programmer/controller to be positioned (for convenience reasons), but am not sure exactly where to position the thermostat. The house is quite drafty, so we may have to try a few places before we find the best one.

I run 2 x 2.5mm Twin & Earth cables from the boiler to the position where the programmer is to be located (I can get mains feed either from the boiler end, and also from near where the programmer is going to be located). I also intend to fix the CMT927 receiver unit very close to the programmer (~1m).

Does that make sense as a set up?

In an earlier contribution to this discussion,
JoeJoe wrote:

Just bought the above wireless thermostat and a separate programmer
to control my combi. Both are 7-day ones. The reason for this setup
is that we do know exactly where we want to programmer/controller to
be positioned (for convenience reasons), but am not sure exactly
where to position the thermostat. The house is quite drafty, so we
may have to try a few places before we find the best one.

I run 2 x 2.5mm Twin & Earth cables from the boiler to the position
where the programmer is to be located (I can get mains feed either
from the boiler end, and also from near where the programmer is going
to be located). I also intend to fix the CMT927 receiver unit very
close to the programmer (~1m).

Does that make sense as a set up?

Not a lot!

The wireless programmable stat is *also* a programmer. If you have two
programmers in series, the heating will only come on when *both* are on. The
fixed programmer is a total waste of time and money - and will have to be
set to 'constant' to allow the programmable stat to work. So replace it with
a short piece of cable!

The base unit for the stat should be as close to the boiler as possible, to
minimise the wiring needed. The sensor unit - which, AIUI also incorporates
the display and programming buttons - can be unhooked from its perch and
taken to your 'convenient' position when you want to change the programme -
and then returned.
--
Cheers,
Roger
______
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"Roger Mills" wrote in message
...
In an earlier contribution to this discussion,
JoeJoe wrote:

Just bought the above wireless thermostat and a separate programmer
to control my combi. Both are 7-day ones. The reason for this setup
is that we do know exactly where we want to programmer/controller to
be positioned (for convenience reasons), but am not sure exactly
where to position the thermostat. The house is quite drafty, so we
may have to try a few places before we find the best one.

I run 2 x 2.5mm Twin & Earth cables from the boiler to the position
where the programmer is to be located (I can get mains feed either
from the boiler end, and also from near where the programmer is going
to be located). I also intend to fix the CMT927 receiver unit very
close to the programmer (~1m).

Does that make sense as a set up?

Not a lot!

The wireless programmable stat is *also* a programmer. If you have two
programmers in series, the heating will only come on when *both* are on.
The fixed programmer is a total waste of time and money - and will have to
be set to 'constant' to allow the programmable stat to work. So replace it
with a short piece of cable!

The base unit for the stat should be as close to the boiler as possible,
to minimise the wiring needed. The sensor unit - which, AIUI also
incorporates the display and programming buttons - can be unhooked from
its perch and taken to your 'convenient' position when you want to change
the programme - and then returned.
--
Cheers,
Roger

Thanks for taking the time to reply, but I perhaps I didn't explain what we
were trying to achieve properly.

We (well, she... always cold...) tend to use the override feature (i.e.
turn it to "constant on" or to "1hr boost") pretty often, and therefore we
want the controls to be in a convenient position. As the downstairs is
drafty, we may end up with the stat in the upstairs landing, so we don't
want to have to use it as the main control for the system. I agree that we
could potentially use a much cheaper/simpler wireless stat, even without any
real programming - but we got a very good deal on the 927, so we got it
anyway.

The plan is to set the stat to pretty much "always on" temperature
throughout the day, and do the time/day control from the conveniently
positioned programmer. The reason we wanted a little smarter stat is to
allow us to experiment with different temperature settings for, say, morning
and evening.

Sorry for not explaining this earlier.

Does it make more sense now?

In an earlier contribution to this discussion,
JoeJoe wrote:


Thanks for taking the time to reply, but I perhaps I didn't explain
what we were trying to achieve properly.

We (well, she... always cold...) tend to use the override feature
(i.e. turn it to "constant on" or to "1hr boost") pretty often, and
therefore we want the controls to be in a convenient position. As the
downstairs is drafty, we may end up with the stat in the upstairs
landing, so we don't want to have to use it as the main control for
the system. I agree that we could potentially use a much
cheaper/simpler wireless stat, even without any real programming -
but we got a very good deal on the 927, so we got it anyway.

The plan is to set the stat to pretty much "always on" temperature
throughout the day, and do the time/day control from the conveniently
positioned programmer. The reason we wanted a little smarter stat is
to allow us to experiment with different temperature settings for,
say, morning and evening.

Sorry for not explaining this earlier.

Does it make more sense now?

I can see what you're setting out to achieve but, in your position, I'd be
attacking the drafts first before worrying about over-complicating the CH
control.

By having another timer in series with your programmable stat you will
negate some of the features of the stat - such as its ability to act as a
frost stat in its 'off' state.

If you want to boost the temperature above the current stat setting at a
time when the main timer is on, you'll have to go to the programmable stat
anyway!
--
Cheers,
Roger
______
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monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!