Wiring Diagrams - nest Learning Thermostat Installation Manual

Wiring diagrams

The following diagrams show you how to install
the Nest Thermostat on:
230 V combi boilers (page 22)
Low voltage/dry contact combi boilers (page 23)
S-plan (page 24)
Y-plan (page 25)
OpenTherm boiler (page 26)
District heating with
electrical control valve
(page 27)
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General specs General specs
Heat Link
Terminal Specification
L 230 V AC/50 Hz mains voltage
N 230 V AC/50 Hz mains voltage
1 Heating relay normally closed
2 Heating relay common
3 Heating relay normally open
4 Hot water relay normally closed
5 Hot water relay common
6 Hot water relay normally open
OT1 OpenTherm wire 1
OT2 OpenTherm wire 2
If using T1 and T2, connect to earth
T1 12 V DC power output to Nest
T2 12 V DC power output to Nest
Note: T1 and T2 have no polarity at the thermostat.
Maximum cable thickness = 2 mm²
AC power adaptor
Input: 100-240 V AC, 50/60 Hz, 0.2 A | Output: 5 V DC, 1.4 A
Notes
Live wire
Neutral wire
3 A resistive, 1 A inductive
3 A resistive, 1 A inductive
3 A resistive, 1 A inductive
3 A resistive, 1 A inductive
3 A resistive, 1 A inductive
3 A resistive, 1 A inductive
42 V DC max.
42 V DC max.
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