Nest Thermostat Wiring

lucifersangel87

Hi all,
I'm saving money by installing my Nest thermostat myself.

My Worcester 28CDi (old style) has a mechanical programmer only, installed to the ST8 bracket, which is used for thermostats and programmers.
The connectors are Ns, Ls, Lr and Spare, which are currently connected as Neutral, Live, Switched Live and nothing is connected to the spare.

The nest has wires "Call for Heat", "Common" and "Satisfied". I'm assuming they match up in order of: Live, Neutral and Live Switched.

So:
Ns = Neutral = Common
Ls = Live = Call for Heat
Lr = Switched Live = Satisfied
Spare = Nothing

Anyone on the board able to advise?

Thanks

Le_Kirk

What does the wiring instruction booklet show? Is there a wiring diagram? I don't think I would be putting Neutral into Common. Common is normally used as the input voltage to a relay which would be switched between Call for heat and Satisfied. Look at the wiring diagram on page 22 of this link.

Alex1983

As above dont put neutral in to common.

Your making it more complicated then it really is. Just take mains power to your heat link and then wire LS to 2 and LR to 3. Dont worry about the satisfied connection or NS its not needed.