Upgrading from Centaurplaus C27 programmer to Nest Gen 3 Heatlink

21 Dec 2022
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United Kingdom
Hi there

I am just in process of upgrading my current Centaurplaus C27 / Drayton Thermostat to a Nest Gen 3 Heatlink. Hoping to get confirmation from the helpful users of this forum on the wiring changes I am proposing to make. Photos of the current wiring setup in the C27 and the Thermostat are attached, along with wiring diagram for Nest.

Please could you let me know if any issues with proposed wiring? Thanks in advance for the help.

Both N in C27 >>>>> N in Heatlink
Both L in C27 >>>>> L in Heatlink
3 in C27 >>>>> 6 in Heatlink
4 in C27 >>>>> 3 in Heatlink
Link L >>>>> 2 and 5 in Heatlink

To remove old thermostat wiring: Trace the wiring from the thermostat back to the wiring centre and remove. Need to put a link in between the two lives (Red and Yellow) at the wiring centre where these two are removed from. Neutral just needs removing.

I plan on just having the Nest Thermostat plugged in to the mains, connected wirelessly to the Heatlink.


  • C27 Programmer.jpeg
    C27 Programmer.jpeg
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  • Drayton Thermostat.jpeg
    Drayton Thermostat.jpeg
    185.4 KB · Views: 79
  • Nest Wiring Diagram.jpeg
    Nest Wiring Diagram.jpeg
    65.1 KB · Views: 76
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All sounds good to me. (y)

If you don't connect the earth wires to the Heat link [The Heat link earth connection is only required if using T1 & T2 to power the Nest thermostat according to the Nest instructions] then make sure the earth wires remain connected together for the parts of your system that do require an earth connection. The metal back box should also have an earth connection if you are keeping it.

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