HELP! New Nest Gen3 with Old System?

[duckdodgersuk]

Hello again , after the Christmas holiday I got round to replacing the wiring station so it’s a bit better.

 

[duckdodgersuk]

Next is the Nest installation, I’m following you guide like this:

 

[duckdodgersuk]

Ok, i've installed the heat link thanks to @stem advice

I put a Wago connector linking L (Red) and the 3 (Yellow) on the old thermostat to test and it works

 

[duckdodgersuk]

Now that I've tested it and its running I want to hard wire the Next thermostat in place as the usb is only 5v

 

[duckdodgersuk]

Which wires should I move to T1 & T2 ?

If I move yellow 2 and red 3 do I need to remove the Blue? also what about the Brown in 2 which controls the pump?

 

[stem]

Disconnect the old thermostat cable (I assume that is RTS) completely from the wiring centre. Then, either add a link to join the terminals where the Red and Yellow wires have just been removed from together. Or simply move the brown wire from terminal 2 to 3 which does the same thing.

The blue neutral, and earth wires are simply disconnected.

That will then leave you with a cable that isn't connected to anything at either end. You can then use that cable to connect the Heat Link terminals T1 & T2 to the corresponding terminals at the thermostat.

 

[duckdodgersuk]

Thank you @stem . I moved the brown wire from 2 to 3 and i've now wired 1 for T1 and 2 for T2

Shows 10.9v but I guess that's because to the power drop because the heat link is upstairs and the thermostat is downstairs.

Thank you again for all your help

 

[stem]

Well done, I'm sure you are going to secure the cable under a wiring centre cable clamp.

 

[duckdodgersuk]

Oh yes, all done