Wiring up a Nest Thermostat

[sturmillar]

Hi Guys,

I'm a newbie here on this site and was looking for a little advice. I'm quite comfortable with electrics, but not so much for heating. I'm trying to hook up a Nest Learning Thermostat to my central heating system. The programmer is a Drayton Tempus 7 and the boiler is a Potterton Suprima 60L. There is a Drayton wired thermostat already installed in the hall which I assume comes back to the programmer here somehow.

I've posted pictures of the Tempus 7 programmer as is, and the wiring diagram. I'm assuming I can simply take a spur from the junction box behind the programmer to the Heat Link 240v to power it. However, the call for heat has me a little confused - can I simply wire the HeatLink into slot 4 on the tempus below, as this seems to control the CH circuit.

Obviously there is an isolating junction box so I can isolate all the electrics safely too.

Any help would be great!

Drayton Tempus 7

• sturmillar
• 10 May 2014
• 1

As is

Programmer Wiring Diagram

• sturmillar
• 10 May 2014
• 1

Nest Install Instructions

• sturmillar
• 10 May 2014
• 2

Nest Install Instructions

• sturmillar
• 10 May 2014
• 1

 

[Dean744PiN5]

You should wire the heat link into the wiring centre for all your heating controls (most likely next to the hot water cylinder) will need to know if you have a y plan or s plan system before can advise further.

 

[sturmillar]

Dean - thanks. I believe this is the only wiring in the system. Behind that plate which mounts the programmer are some junction connections including cables to the boiler.

From what I can make out the thermostat is wired in series somehow to the connection labelled 4. The call for heat connections are behind but don't appear to be connected to the programmer.

I believe it is a Y plan system.

 

[Barney123m]

Hi Sturmillar, did you manage to work it out as I have exactly the same problem? My existing Honeywell has same connections as yours and trying to install a nest. Thanks