Wiring a Honeywell CMT927 Thermostat

[captainmerky]

Hi,
I need help please! I have bought a Honeywell CMT927 Thermostat with a view to saving some money on heating bills. Trouble is, so far I have spent a fortune trying to have it installed - two electricians have tried and failed! Is there anyone in the London area (north) who can install one of these things? It is to go with a Bosch combi boiler.

[neilball]

I'm assuming the CM927 has the HC60NG wireless receiver.

The HC60NG goes next to the boiler and requires a permanent live & neutral connection (usually fed from the same supply as the boiler so both are isolated by a common fused/switched spur) to power the unit and the relay terminals (A & B) wire to the room stat connections in the boiler which usually have a wire link that the electrician removes when connecting the controls.

It is as easy as it gets to connect so if the electrician cannot work it out then I would be worried about his competency! There is even a simple wiring diagram in the CM927 installation instructions that shows a combi-boiler and although the terminal numbers will be different in the boiler it is not hard to look up the corresponding digram in the boiler manual.

The electrican can test the HC60NG is wired correctly by pressing the button on the front of the unit - this switches the relay on & off (if the HC60NG has been paired to the CM927 then a green LED will light on the HC60NG when it is calling on the boiler) and will fire up the boiler & run the pump when calling for heat.

[captainmerky]

Hi Neil,

Thanks for the reply. Yes I do have the wireless receiver. From everything I have read about this thermostat, I am indeed questioning the competency of the electricians who have tried to install it so far.

I managed to speak to Honeywell this morning and a very helpful lady there was able to talk me through the installation procedure. She said pretty much all that you said in your reply. I have a mate who is not afraid of electrics (I have to admit anything over 12V and I panic!) and I will ask him to have a look at it with me, your instructions and the electrician. I am hopeful that we will be able to get it connected.

Appreciate the help.

[fblasot]

Hi, I'm from Italy and a little bit OT so excuse me...
I'm thinking to buy this Thermostat on ebay from a english user.
The product model is specific for UK (CMT927A1049).
I downloaded the user manual and I understood that time (via setup) can be displayed in 12/24h format.
What about the date format ? Is it dd/mm/yy or mm/dd/yy ?
Any chances to change language displayed ?

Thanks.