Replace British Gas UP2 with Nest 3rd Gen Theromstat

[Lch]

Hi - trying to replace my British Gas UP2 with Nest 3rd Gen Thermostat.

Picture of UP2 wiring:
[GALLERY=media, 101950]Image-2 by Lch posted 29 Sep 2018 at 4:30 PM[/GALLERY]

Did the following configuration:
UP2 'N' (blue) goes to Nest 'N'
UP2 'L' (red) goes to Nest 'L'
UP2 'Ground' (yellow/green) goes to Nest 'Ground'
UP2 '3' (HW ON/black) goes to Nest '6'
UP2 '4' (CH ON/yellow) goes to Nest '3'

I am not getting any heating from my radiators. Any thing wrong with my config above?

Thanks in advance,
L

 

[stem]

For a start sort out that neutral connection. The conductor should be securely fixed under the clamp without any whiskers poking out.

Second, have you linked the Nest Heatlink common terminals 2, and 5, to the L terminal?

Next, do you have / did you have an existing room thermostat before the Nest was installed? If so, have you decommissioned it properly? It cannot just be disconnected otherwise the the heating wiring will be 'open circuit' and will not come on. If the existing thermostat is still wired in, simply turn it to its maximum setting and the Nest will take over control. If you have removed it, or plan to do so, the terminals where its switching wires were connected to, need to be joined together.

 

[dang32]

as above. needs links from L to commons

 

[Lch]

Thanks for the quick response, much appreciated.

Besides links from the L to commons, are all the wiring correct?

[GALLERY=media, 101951]9231F0C3-EEA8-46AE-AC9C-559A5FFDDBDA by Lch posted 29 Sep 2018 at 7:05 PM[/GALLERY]

 

[Lch]

Next, do you have / did you have an existing room thermostat before the Nest was installed? If so, have you decommissioned it properly? It cannot just be disconnected otherwise the the heating wiring will be 'open circuit' and will not come on. If the existing thermostat is still wired in, simply turn it to its maximum setting and the Nest will take over control. If you have removed it, or plan to do so, the terminals where its switching wires were connected to, need to be joined together.

I still have my british gas wireless WL1 and receiver BR2 intact. Is it better to turn to maximum setting or remove it completely?

Thanks in advance!

 

[dang32]

should work with links in

 

[stem]

Looks OK apart from the missing link between 'L' and the two commons, '2' and '5'. This is clearly shown in the Nest Instructions. I have highlighted it in brown for you here.

I still have my british gas wireless WL1 and receiver BR2 intact. Is it better to turn to maximum setting or remove it completely?

To do it properly, a professional would decommission and remove the existing thermostat, but do not just remove it. If you aren't able to decommission it properly and link the wiring out as I described previously, then leave it in place but on the maximum setting.