Nest Learning Thermostat D3 Operation Manual

The Nest Learning Thermostat D3 (3rd Generation) is a smart, Wi-Fi enabled thermostat that learns your schedule and preferences to optimize comfort and energy savings. It supports multi-stage heating/cooling systems and integrates with the Google Home 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: Smart learning thermostat for multi-stage heating and cooling systems
Compatibility:
- 95% of 24V HVAC systems: gas, electric, oil, forced air, heat pump, radiant
- Heating: 1-3 stages (W1, W2, W3)
- Cooling: 1-2 stages (Y1, Y2)
- Heat pump with aux/emergency heat (O/B, AUX, E)
- Humidifier/dehumidifier (HUM, DEHUM)
- Fan: 1-3 speeds (G, G1, G2, G3)
Power Source:
- Voltage: 20-30 VAC
- Battery: Built-in rechargeable lithium-ion
- Power consumption: Less than 1 kWh/month
Electrical Rating:
- Supports systems without C-wire (Nest Power Connector optional)
- * connector: One of W3, E, HUM, DEHUM, G3
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
- Altitude: Up to 10,000 ft
Dimensions: 3.3" D x 3.3" W x 1.1" H; Weight: 1 lb
Features:
- Auto-Schedule learning
- Wi-Fi: 802.11b/g/n (2.4/5 GHz), Bluetooth Low Energy
- 24-bit color LCD (480x480 resolution)
- Sensors: Temperature, humidity, proximity, motion, ambient light
- Energy Star certified
Thermostat Configuration Options:
- Maximum stages Heat/Cool: 3/2
- Voice control: Google Assistant, Amazon Alexa
- App integration: Google Home/Nest app

Operation Instructions

Initial Setup

1. Power On: Restore power to HVAC after installation; thermostat starts up.
2. Download App: Install Google Home or Nest app, create account.
3. Configure System:

Select language, connect to Wi-Fi, confirm location.
Identify heating/cooling equipment, run system test.
Pair via QR code or entry key; thermostat learns 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. Fan Control: Configure in app: Auto or On.
4. Manual Override: Turn ring for temporary hold; resumes after period.

Operating in Programmable Mode

1. Factory Schedule: Default with Comfort, Eco, Sleep temperatures; Auto-Schedule learns preferences.
2. Custom Schedule:

Press ring to menu > Schedule, or use app: Devices > Thermostat > Schedule.
Set times/temps for periods; copy to days.
Enable Auto-Schedule for optimizations.

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. Early-On: Pre-heats/cools to reach setpoint on time.
2. Home/Away Assist: Auto-Eco using sensors/phone location.
3. Energy History: Tracks usage in app; Nest Leaf for efficient temps.
4. Voice Control: "Hey Google, set thermostat to 72°" or Alexa.
5. HVAC Monitoring: Alerts for issues via app.

Troubleshooting

No Power: Check breaker, wiring; charge battery if red light.
Wi-Fi Issues: Restart router, verify password; check nest.com/support.
No Heat/Cool: Confirm mode, setpoint; check E/N errors in setup.
Errors: E (wiring, e.g., E89 Y2 without Y1); N (non-critical); W (Wi-Fi, e.g., W3 no IP).

Installation Instructions

Warning: Turn off power at breaker. Professional install recommended for complex systems. Check compatibility at nest.com/works.

Remove Old Thermostat

Switch off HVAC power.
Remove cover, photo wiring.
Remove jumpers, label wires.
Disconnect wires, remove base.

Installing New Thermostat

Base: Mark/level position, attach to wall (trim plate optional).
Wires: Pull through base, connect per labels.
Attach: Snap display onto base.
Power On: Restore power, run setup.

Battery Location

Built-in rechargeable lithium-ion in display.
Charges from 24V wires; C-wire optional.

Wiring and Configuration

Strip 1/4-3/8", no polarity. Follow app diagram.

Terminal	Description
Rh/Rc	Power (auto-jump)
W1/W2/W3	Heat stages
Y1/Y2	Cool stages
G	Fan
O/B	Changeover
AUX/E	Aux/emergency
C	Common
*	HUM/DEHUM/E/W3/G3

Caution: Configure in app; test system.