Honeywell CM907 Connections

[soaker]

Hi,

Anybody know the equivilent wiring connections from a Honeywell T61608 Room Stat, with connections on 2 - BL 3 - Y and 1 - R to a new Honeywell CM907 ?

 

[mario500]

Don't need the blue so tape it up. Red should be one I think and yellow 3.

The wiring diagram with the Honeywell is very good.
What system are you putting it on?


AL

 

[soaker]

Don't need the blue so tape it up. Red should be one I think and yellow 3.

The wiring diagram with the Honeywell is very good.
What system are you putting it on?


AL

Hi AL
the existing system is a ST699 Programmer and a mid position valve Tank Stat and Pottertom Bioler gravity fed hot water

 

[mario500]

The Honeywell cm907 is a chronotherm programmable stat. I would say that it is a bit overkill for the Y plan system that you have.

I personally would install a basic digistat which would measure the air temp very well and would have a digital display.

A cm907 is more suited for a combi boiler installation or even an air conditioning unit - where set on/off times are required.

Although it will work on the system you have - it will not bring the boiler on if your programmer is not calling for heat.

Hope this helps


AL

 

[D_Hailsham]

The Honeywell cm907 is a chronotherm programmable stat. I would say that it is a bit overkill for the Y plan system that you have.

Why overkill in a Y plan? The cm907 does everything you need to control the heating times and temperatures. What more could anyone ask for?

A cm907 is more suited for a combi boiler installation or even an air conditioning unit - where set on/off times are required.

Are you suggesting that people with Y plan do not need set on/off times?

Although it will work on the system you have - it will not bring the boiler on if your programmer is not calling for heat.

So you either set your existing programmer to continuous CH, and let the CM907 control times and temperatures; or you wire the CM907 back to a permanent live in the wiring centre, missing out the existing programmer completely. The existing programmer will continue to be used to control hot water times, which do tend to remain fixed.

 

[soaker]

The Honeywell cm907 is a chronotherm programmable stat. I would say that it is a bit overkill for the Y plan system that you have.

Why overkill in a Y plan? The cm907 does everything you need to control the heating times and temperatures. What more could anyone ask for?

A cm907 is more suited for a combi boiler installation or even an air conditioning unit - where set on/off times are required.

Are you suggesting that people with Y plan do not need set on/off times?

Although it will work on the system you have - it will not bring the boiler on if your programmer is not calling for heat.

So you either set your existing programmer to continuous CH, and let the CM907 control times and temperatures; or you wire the CM907 back to a permanent live in the wiring centre, missing out the existing programmer completely. The existing programmer will continue to be used to control hot water times, which do tend to remain fixed.

Thanks D_Hailsham& Mario for the info, any idea what the wiring connections would be from the existing room stat to cm907 are they as been quoted earlier by Mario 500

 

[D_Hailsham]

any idea what the wiring connections would be from the existing room stat to cm907 are they as been quoted earlier by Mario 500

Yes, as Mario said earlier: Red to A an Yellow to B. The blue wire is not needed and should be made safe (insulating tape) at both ends. I would also move the red, at the other end, to a permanent live - normally terminal 1 in the wiring centre. This prevents the accidental turning off of the heating at the old programmer, which still controls hot water times.

 

[mario500]

Why have two programmers? what on earth for? Just my thoughts, but I personally would install a basic room stat with a digital display.

I guess the other consideration is which controller is more convienient? the origional programmer or the location of the stat.
If say for example the programmer is in the airing cupboard, but the stat is in the hall - then installing a CM would be a good idea.

Otherwise a waste of money if you ask me.

One bit of advice - when programming your set on/off times - make sure the off periods have a low temp setting ie 5 degrees or something - otherwise the blimin thing will never turn off!!!!

This product is not a programmer (acording to Honeywell it is a chronotherm stat) So it is designed to bring on the heating even in the off periods when the (off) temp is calling for heat.

Hope that makes sense for you.


Al

 

[soaker]

excellent folks thank you kindly for your replies you've been really helpful

 

[D_Hailsham]

Why have two programmers? what on earth for? Just my thoughts, but I personally would install a basic room stat with a digital display.

I think you will find that the OP has already bought the CM907.

I won't answer your first two questions - the answer is obvious if you think about it.

 

[mario500]

It is possible to take stuff back to shops you know!

nah nah ne nah nah