Related to the "Jobs are too small" thread below. I have been encourged by
some of you to at least have a go with trying to do the thermostat myself
with your help and guidance, so here goes!

I currently have a Drayton room stat like this one http://tinyurl.com/25kle

I want to replace it with Honeywell CM67.

I have looked at the wiring on the Drayton and it is as follows:

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3

I have looked at the instructions (and I've looked inside) of the honeywell,
there are 3 terminals, which is my first confusion as I have 4 wires! They
are labeled (A), (B) and (C). On the instructions there are 4 wiring
diagrams that are double dutch to me!! I have looked at the honeywell
website to see if they have installattion manuals I can refer you to but
they don't for this thermostat, just the RF version which looks very
different from this one.

I know this is a popular thermostat as I got the recoomendation from here,
so hopefully some of you will be very familiar with it and you can tell me
exactly which wire goes where and what I do with the left over one????

Thanks in advance.

Angela

I have found the installation guide on the internet

http://content.honeywell.com/uk/home...l/CM/cm67i.pdf

This is more confusing that the leaflet that came with this stat as it has 8
wiring diagrams rather than the 4 I have!! The diagrams I have are a, b, f
and g

Angela

AK wrote:
Related to the "Jobs are too small" thread below. I have been encourged by
some of you to at least have a go with trying to do the thermostat myself
with your help and guidance, so here goes!

I currently have a Drayton room stat like this one http://tinyurl.com/25kle

I want to replace it with Honeywell CM67.

I have looked at the wiring on the Drayton and it is as follows:

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3

I have looked at the instructions (and I've looked inside) of the honeywell,
there are 3 terminals, which is my first confusion as I have 4 wires! They
are labeled (A), (B) and (C). On the instructions there are 4 wiring
diagrams that are double dutch to me!! I have looked at the honeywell
website to see if they have installattion manuals I can refer you to but
they don't for this thermostat, just the RF version which looks very
different from this one.

I know this is a popular thermostat as I got the recoomendation from here,
so hopefully some of you will be very familiar with it and you can tell me
exactly which wire goes where and what I do with the left over one????

Thanks in advance.

Angela


Angela,
As repeated from my other post, thermostats are at mains voltage so turn
everything off before you start.

I suggest you unscrew the existing thermostat and peek inside, how many
wires have you actually got in there?

Secondly, what controls when your heating comes on at present as you may
need to consider how it will interact with the CM67?

Nick Brooks

"Nick Brooks" wrote in message
...

Hi Nick

I suggest you unscrew the existing thermostat and peek inside, how many
wires have you actually got in there?

I looked inside the drayton and this is what was inside

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3

Secondly, what controls when your heating comes on at present as you may
need to consider how it will interact with the CM67?

The boiler has a timer on it but I understand that doesn't matter I just
switch it over from timer to to constant and let the thermostat control it.

Angela

AK wrote:
"Nick Brooks" wrote in message
...

Hi Nick


I suggest you unscrew the existing thermostat and peek inside, how many
wires have you actually got in there?


I looked inside the drayton and this is what was inside

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3


Secondly, what controls when your heating comes on at present as you may
need to consider how it will interact with the CM67?


The boiler has a timer on it but I understand that doesn't matter I just
switch it over from timer to to constant and let the thermostat control it.

Angela


Sorry I didn't read your post carefully enough, and I didn't mean to
sound patronising either :-)

The CM67 is battery powered so won't need the neutral (blue) wire. You
ought to terminate it in an insulated block to make sure it can't touch
anything.

Connect the live to terminal A
Connect the Yellow (switched live) to terminal B

I can't remeber the earthing arrangement for the CM67 but my bet is that
it's double insulated and doesn't need the earth either so connect that
to the metal box in the wall if there is one.

Hope this helps

Nick Brooks

In an earlier contribution to this discussion,
AK wrote:

Related to the "Jobs are too small" thread below. I have been
encourged by some of you to at least have a go with trying to do the
thermostat myself with your help and guidance, so here goes!

I currently have a Drayton room stat like this one
http://tinyurl.com/25kle

I want to replace it with Honeywell CM67.

I have looked at the wiring on the Drayton and it is as follows:

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3

I have looked at the instructions (and I've looked inside) of the
honeywell, there are 3 terminals, which is my first confusion as I
have 4 wires! They are labeled (A), (B) and (C). On the
instructions there are 4 wiring diagrams that are double dutch to
me!! I have looked at the honeywell website to see if they have
installattion manuals I can refer you to but they don't for this
thermostat, just the RF version which looks very different from this
one.

I know this is a popular thermostat as I got the recoomendation from
here, so hopefully some of you will be very familiar with it and you
can tell me exactly which wire goes where and what I do with the left
over one????

Thanks in advance.

Angela

You only need to connect 2 of the 4 wires to the CM67 - the other 2 are
redundant.

Firstly, the CM 67 does not need - and has no provision for - an earth wire.
Secondly, it doesn't need a neutral connection - and the neutral wire must
*not* be connected - otherwise you'll get a dead short under certain
conditions. [Your old stat has an accelerator heater inside to improve its
response, and the neutral provides the return for that. Digital stats don't
need internal heaters]

The built-in switch is a change-over switch which has a Common connection
(A) and two further contacts (B and C). When the room temperature is below
the set temperature, A is connected to B. When the set temperature is
reached, the contacts change over so that A connects to C.

However, for straight heating, you only need to use it as an on/off switch -
and only need to use terminals A and B. So, connect the red wire to A and
the yellow wire to B - and chop the other 2 wires off.

When I fitted mine, I put it in a slightly different place from the
original, and had to extend the wires. So I terminated the original cable in
a 4-way junction box inside a cupboard, and then used a 2-core cable for the
extension to the stat. Works a treat!

Come back if you start having fun programming it!
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

On Thu, 25 Mar 2004 16:40:32 -0000, in uk.d-i-y you wrote:

"Nick Brooks" wrote in message
...

Hi Nick

I suggest you unscrew the existing thermostat and peek inside, how many
wires have you actually got in there?

I looked inside the drayton and this is what was inside

Blue wire to N
Red wire to L
Earth (green & yellow) to earth
Yellow wire to a terminal numbered 3

Secondly, what controls when your heating comes on at present as you may
need to consider how it will interact with the CM67?

The boiler has a timer on it but I understand that doesn't matter I just
switch it over from timer to to constant and let the thermostat control it.

Likely OK if you have a fully pumped system. If you have gravity H/W
circulation then you may end up with the boiler on all the time (i.e.
heating H/W). Floor standing boilers sometimes have gravity H/W
circulation. I dont think that wall mounted boilers ever use gravity
circultaion.

Michael Chare

On Thu, 25 Mar 2004 17:35:51 -0000, in uk.d-i-y "Set Square"
strung together this:

So, connect the red wire to A and
the yellow wire to B - and chop the other 2 wires off.

Not a good idea, I thought better of you! I think you were meant to
write, make the existing wires safe, in a connector. If the stat is
mounted on a metal box then connect the earth to the box and put the
neutral in a connector.
Or, disconnect the unused wires in the junction box in the airing
cupboard.
--

SJW
A.C.S. Ltd.

In an earlier contribution to this discussion,
Lurch wrote:

On Thu, 25 Mar 2004 17:35:51 -0000, in uk.d-i-y "Set Square"
strung together this:

So, connect the red wire to A and
the yellow wire to B - and chop the other 2 wires off.

Not a good idea, I thought better of you! I think you were meant to
write, make the existing wires safe, in a connector. If the stat is
mounted on a metal box then connect the earth to the box and put the
neutral in a connector.
Or, disconnect the unused wires in the junction box in the airing
cupboard.

Maybe I should have stressed that they should be dealt with in a way which
prevents them from touching anything live.

I did go on to explain how I had dealt with my own wires - by terminating
them in a junction box. If the OP copies that, it will be perfectly safe.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is Black Hole!

What great people you all are - it took me 15 minutes to do, it was very
simple. Thank you. It did however take me 45 minutes to programme the darn
thing, but I have it sussed now!

Thanks again

Angela