Nest T3031EX Thermostat Operation Manual

The Nest T3031EX (Learning Thermostat 3rd Gen, Premium EU/UK) is a smart, Wi-Fi enabled thermostat that learns your schedule and preferences to optimize comfort and energy savings. It supports premium central heating, advanced zoning, cooling, and hot water systems. Requires Heat Link for 230V AC setups. Integrates with Google Nest app for remote control. Below are the key specifications and operation instructions.

1. Key Specifications 2. Operation Instructions 2.1. Initial Setup 2.2. Setting the Clock and Day 2.3. Operating in Non-Programmable Mode 2.4. Operating in Programmable Mode 2.5. Advanced Features 2.6. Troubleshooting 3. Installation Instructions 3.1. Remove Old Thermostat 3.2. Installing New Thermostat 3.3. Battery Location 3.4. Wiring and Configuration

Key Specifications

Type: Premium smart learning thermostat for advanced multi-zone heating, cooling, and hot water
Compatibility:
- Premium EU/UK systems: High-end combi/system boilers, advanced heat pumps, multi-zone S/Y-plan, district heating, radiant underfloor
- On/Off, OpenTherm, and extended modulating control
- Heating: 1-3 stages; Cooling: 1-2 stages; Dual-zone hot water
- Supports up to 3 additional sensors for zoning
Power Source:
- 230 V AC/50 Hz via Heat Link
- Battery: Built-in rechargeable lithium-ion
- Power consumption: Less than 1 kWh/month
Electrical Rating:
- Heat Link: 5 A resistive/2 A inductive per relay
- OpenTherm: 42 V DC max
- ErP Class III (On/Off) / V (OpenTherm)
Temperature Range: Setpoint: 40°F to 90°F (4° to 32°C); Operating: 32°F to 104°F (0° to 40°C)
Operating Conditions:
- Humidity: Up to 90% RH non-condensing
- Wireless range: Up to 50 m with extenders
Dimensions: Display: 3.3" diameter x 1.06" H; Heat Link: 4" x 3" x 1.2"; Weight: 9 oz (display)
Features:
- AI-driven Auto-Schedule and predictive learning
- Wi-Fi (802.11 a/b/g/n), Bluetooth Low Energy
- High-res 24-bit color LCD (480x480)
- Advanced sensors: Temperature, humidity, proximity, motion, light, air quality
- Energy Star/ErP certified with premium efficiency
Thermostat Configuration Options:
- Maximum stages Heat/Cool: 3/2 with zoning
- Multi-room sensor integration
- App/voice control (Google Assistant, Alexa, Siri)

Operation Instructions

Initial Setup

1. Professional Install: Wire Heat Link for premium zoning (see Section 3).
2. Power On: Mains power activates Heat Link; display pairs automatically.
3. Configure System:

Download Nest app, scan QR, secure Wi-Fi connection.
Select premium system (multi-zone, radiant, etc.), calibrate sensors.
Input home layout; AI learns advanced patterns from day one.

Setting the Clock and Day

1. Syncs automatically via Wi-Fi.
2. Manual: Press ring to menu, turn to Settings > Clock, press to select.
3. Adjust time zone, format (12/24-hour), daylight savings.
4. Day of week auto-detected from schedule and location.

Operating in Non-Programmable Mode

1. Select Mode: Press ring toward wall to open menu, turn to Off, Heat, Cool, Eco.
2. Adjust Temperature: Turn outer ring clockwise to increase, counterclockwise to decrease.
3. Zone Control: Adjust per room via app or voice.
4. Manual Override: Turn ring for temporary hold; resumes after period.

Operating in Programmable Mode

1. Factory Schedule: Premium defaults with zoning; AI refines over time.
2. Custom Schedule:

Press ring to menu > Schedule, or app: Devices > Thermostat > Schedule.
Set times/temps per zone, heat, hot water; integrate sensors.
Enable predictive Auto-Schedule for proactive adjustments.

3. Temporary Override: Turn ring to adjust.
4. Permanent Hold: Select Hold in menu/app.
5. Disable Programming: Set manual mode in app.

Advanced Features

1. Smart Zoning: Balances temps across rooms with sensor data.
2. Air Quality Monitor: Alerts and auto-ventilation integration.
3. Farsight Pro: Customizable display for weather, alerts, or calendar.
4. Energy Analytics: Advanced reports with predictive savings forecasts.
5. Optimizes for premium radiant and heat pump systems.

Troubleshooting

No Power/Link: Check mains, Heat Link status LEDs; factory reset.
Zone Imbalance: Recalibrate sensors in app; check wiring.
Wi-Fi Drop: Use extender; firmware update via app.
Error Codes: E.g., E2 (sensor fault); detailed diagnostics in app.

Installation Instructions

Warning: 230V AC; certified professional only. Comply with local electrical codes; isolate power.

Remove Old Thermostat

Isolate mains power.
Dismantle old thermostat, document all zone wires.
Safely cap unused wires.

Installing New Thermostat

Heat Link: Secure mount near boiler; wire L/N mains, advanced relays (1-3/4-6/7-9 for zones), OT1/OT2.
Extended Wiring: Route screened T1/T2 to display; add sensor hubs if multi-room.
Display Base: Mount optimally (1.5m height); connect T1/T2.
Assemble: Snap display; pair sensors.
Commission: Power on, app-guided calibration and test.

Battery Location

Integrated rechargeable lithium-ion in display.
Self-maintaining; app monitors health.

Wiring and Configuration

Max 1.5 mm² for controls; use ferrules for multi-strand.

Heat Link Terminal	Description
L/N	230V AC mains
1-3 (NC/C/NO)	Primary heating zone
4-6 (NC/C/NO)	Secondary hot water/zone
7-9 (NC/C/NO)	Extended zone relay
OT1/OT2	Modulating boiler link
T1/T2	Wireless to display/sensors

Caution: 50 cm clearance for Heat Link; premium config in app for zoning/sensors.