CMT921 - CMT927 Difference?

[1009049football]

Hi guys,

neewbie on this forum so please treat me kindly!

I have an antique Worcester Heatslave Highflow combi which we are currently in the process of reviewing for replacement.
The boiler itself is working perfectly.
However we want to instal a Honeywell programmer/thermostat.

I have already ordered a Honeywell CMT921 but I understand the CMT927 is better.

Could someone please tell me the basic differences in them.

Also is it simply DIY to instal either.

Thank you B

 

[namsag]

927 can be set up different for every day 921 same progammes for every day.
Doddle to fit

 

[D_Hailsham]

I have already ordered a Honeywell CMT921 but I understand the CMT927 is better.

Could someone please tell me the basic differences in them.

Also is it simply DIY to instal either.

The CMT921 is a 24 hour timer, so you will have exactly the same settings every day of the week. The CMT927 is a seven day timer, so you have separate settings for every day of the week.

Installation is very easy. What timer and thermostat do you have at the moment?

 

[1009049football]

I have already ordered a Honeywell CMT921 but I understand the CMT927 is better.

Could someone please tell me the basic differences in them.

Also is it simply DIY to instal either.

The CMT921 is a 24 hour timer, so you will have exactly the same settings every day of the week. The CMT927 is a seven day timer, so you have separate settings for every day of the week.

Installation is very easy. What timer and thermostat do you have at the moment?

I only have the current timer on the Worcester boiler and the basic temperature controls.
No roomstats at all, I am told we could/should have a considerable saving with the Honeywell?
Thank you.

 

[sambotc]

Not sure about considerable but you should save. There is a link in the boiler which needs removing and connecting to A + B on the cm921 , along with a live and neutral from either the boiler terminals (could use 4 core for all) or the fused spur which the boiler is wired into.

Set the built in timer to constant and away you go.


HTH Sam

 

[steviebobs]

Mr Football

Just as an added boost to your confidence - I did the same replacement recently with the 921 ( the Daily version, not the 927 Weekly programmer) and as mentioned by the previous pros, it is a doddle, and incidentally works a treat !! I have my programmer located in the lounge where I can over-ride as necessary.

As a retiree, I decided against the 927 because I cannot predict a week like a 'working person' can, ie weekends are different to work/week days. My days are all weekends !!!!!
So it means I have programmed a typical day, but simply over-ride via the 'Manual' position if the day is 'out of the normal'.

ALSO - heed the 'regular' guys on this site - they are spot on helpfull!!

SB

 

[rebrov85]

Both of these Honeywell timers are universal wireless room thermostats. The only real difference is in the time settings that are open to you.

The CMT 921 gives you 1 time setting, so the room temperatures will be the same from day to day.
http://www.directheatingsupplies.co...eless-1-Day-Programmable-Room-Thermostat.aspx

The CMT 927 is a 7 day room thermostat, so you can set a different tempeature on different days across the week if you wish.
http://www.directheatingsupplies.co...Programmable-Room-Thermostat-CMT927A1049.aspx

You are essentially paying for more control & timing options:

 

[mogget]

Holy thread resurrection Batman!

And is there an echo in here?

 

[rebrov85]

Whoops - bypassed the original post dates!

 

[Charnwood]

The CMT 921 gives you 1 time setting,

Errr, it gives you 6 customisable time/temperature zones over a single 24 hour period.

The CMT 927 is a 7 day room thermostat, so you can set a different tempeature on different days across the week if you wish.

Close, but no cigar.

you can set six different time zones with different temperatures on different days across the week.

And to think we waited 3 years for this.

 

[mrgas]

Six

 

[Dan Robinson]

Don't forget the party and day off buttons

 

[Charnwood]

As a retiree......I cannot predict a week like a 'working person' can, ie weekends are different to work/week days. My days are all weekends !!!!!

The phrase I use: Every night's a Friday night, every day is a Saturday.
Five months down the line and still loving it.

 

[mrgas]

Don't forget the party and day off buttons

I love the glass of wine button!