How to Install a Nest Learning Thermostat — UK Wiring
The Nest Learning Thermostat cuts UK heating bills 8–15% by learning your schedule. The tricky part is wiring the Heat Link into your boiler. Here is every common UK config.
Step-by-step method
1. Turn off power at the fused spur
Isolate the boiler at the 3A fused spur. Test with a voltage tester before touching wires.
2. Identify your existing setup
Combi with mains-powered stat: replace at boiler with Heat Link. S-Plan/Y-Plan with cylinder: Heat Link at wiring centre. Battery-only stat: use Heatlink wiring diagram A.
3. Wire the Heat Link
L, N and Earth from spur. Terminals 3 (call for heat) and 4 (common) to boiler CH terminals. For hot water on a cylinder, add terminals 5 and 6.
4. Mount the Nest display
Screw the base plate at 1.5m height, ideally hallway, away from radiators/draughts. Snap on the display — pairs automatically.
5. Pair with the Nest app
Download Nest app (or Google Home for 4th gen), scan the QR on the display back. Set your Away/Home schedule.
Frequently asked questions
Does Nest work with a combi boiler?+
Yes — any modern UK combi with a 230V or volt-free stat input. Older millivolt systems (pre-1985) may need an interface.
Nest vs Hive vs Tado?+
Nest learns automatically, Hive is simplest to fit (British Gas installer network), Tado has room-by-room TRV control. All cut bills similarly.