1. Introduction
This manual provides instructions for the installation, operation, and maintenance of your Honeywell THX321WFS3001W T10+ Pro Smart Thermostat and Indoor Air Sensor. Please read this manual thoroughly before use to ensure proper functionality and to maximize the benefits of your new smart thermostat system.
2. Product Overview
The Honeywell T10+ Pro Smart Thermostat Kit offers advanced control over your home's heating and cooling, allowing you to prioritize comfort in specific rooms. It integrates seamlessly with humidification, dehumidification, and ventilation systems without requiring new wiring for accessories. The system includes a 7-day programmable touchscreen thermostat and an indoor air sensor.
Key Features:
- Customizable heating and cooling control.
- Integration with humidification, dehumidification, and ventilation.
- RedLINK 3.0 compatibility for indoor temperature, humidity, and motion sensors (up to 20 sensors).
- Flexible scheduling: geofence technology, programmed schedules, or a combination.
- Location-based temperature control for energy saving.
- Smart scheduling with Sleep period.
- Touchscreen interface.

Figure 2.1: Honeywell T10+ Pro Smart Thermostat and Indoor Air Sensor. This image shows the main thermostat unit alongside the smaller indoor air sensor, both in white, displaying temperature and time.
3. Setup and Installation
This section provides general guidance for setting up your Honeywell T10+ Pro Smart Thermostat. Professional installation is recommended for complex HVAC systems.
3.1 Compatibility
The thermostat is compatible with 24 VAC systems, including:
- Up to 3 Heat/2 Cool heat pump systems (4 heat with T10+ & EIM).
- Up to 2 Heat/2 Cool conventional systems (3 Heat/2 Cool with T10+ & EIM).
- Dual Fuel systems.
- Radiant hot water systems, including hot water fan coil.
- Humidification, dehumidification, or ventilation systems (all three with T10+ & EIM).
3.2 Wiring the Thermostat
Ensure power to your HVAC system is turned off at the circuit breaker before beginning any wiring. The thermostat base provides clear terminals for connection.

Figure 3.1: Rear view of the Honeywell T10+ Pro Smart Thermostat wiring base and UWP. This image displays the terminal block for wiring connections and a wire stripping guide, indicating the required wire length for proper installation.
- Power Off: Turn off power to your heating/cooling system at the circuit breaker.
- Remove Old Thermostat: Carefully remove your old thermostat from the wall. Take a picture of the wiring for reference.
- Mount Thermostat Base: Mount the new thermostat's wiring base to the wall using the provided hardware.
- Connect Wires: Connect the wires from your HVAC system to the corresponding terminals on the thermostat base. Refer to the wiring diagram provided with your specific installation guide.
- Attach Thermostat: Secure the T10+ Pro Smart Thermostat head unit to the mounted wiring base.
- Power On: Restore power to your HVAC system.
3.3 Indoor Air Sensor Installation
The RedLINK 3.0 indoor air sensor can be placed in rooms where you want to prioritize temperature and humidity monitoring. Up to 20 sensors can be connected to the thermostat.

Figure 3.2: Front view of the Honeywell T10+ Pro Smart Thermostat Indoor Air Sensor. This image shows the compact, white rectangular sensor unit with "Honeywell Home" branding.

Figure 3.3: Side view of the Honeywell T10+ Pro Smart Thermostat Indoor Air Sensor. This image provides a profile view of the sensor, highlighting its slim design.
- Placement: Choose a central location in the desired room, away from direct sunlight, drafts, or heat sources.
- Pairing: Follow the on-screen instructions on your T10+ Pro Smart Thermostat to pair the indoor air sensor. This typically involves pressing a button on the sensor and confirming on the thermostat.
4. Operating Instructions
The T10+ Pro Smart Thermostat features an intuitive touchscreen interface and smart capabilities for convenient control.
4.1 Basic Operation
- Temperature Adjustment: Tap the up or down arrows on the touchscreen to adjust the desired temperature.
- System Mode: Select between Heat, Cool, Auto, or Off modes.
- Fan Mode: Choose between Auto or On for the fan operation.
4.2 Scheduling
The thermostat offers flexible scheduling options to optimize comfort and energy savings.
- 7-Day Programmable: Set custom schedules for each day of the week.
- Location-Based Control (Geofencing): Utilize your smartphone's location to automatically adjust temperature settings when you leave or return home. This feature helps save energy when the home is unoccupied and ensures comfort upon arrival.
- Smart Scheduling: Incorporate a "Sleep" period into your location-based schedule for optimized nighttime comfort and energy efficiency.
4.3 Using Indoor Air Sensors
Indoor air sensors provide localized temperature, humidity, and motion detection.
- Temperature Averaging: Sensors can be used in combination to average the temperature across multiple rooms, providing more balanced comfort.
- Priority Zones: Based on motion detection, you can select priority zones to ensure the thermostat maintains the desired temperature in occupied areas. This can also be scheduled.
4.4 Smart Home Integration
The T10+ Pro Smart Thermostat is compatible with popular smart home platforms.
- Amazon Alexa: Control your thermostat using voice commands.
- Google Assistant: Integrate with Google Assistant for voice control and smart home routines.
5. Maintenance
Regular maintenance ensures optimal performance and longevity of your thermostat system.
- Cleaning: Gently wipe the touchscreen and thermostat body with a soft, damp cloth. Avoid abrasive cleaners or solvents.
- Sensor Placement: Ensure indoor air sensors remain unobstructed and are not exposed to extreme temperatures or humidity, which could affect readings.
- Battery Replacement: If your indoor air sensors use batteries, replace them as indicated by the thermostat or sensor's low battery indicator.
6. Troubleshooting
This section addresses common issues you might encounter with your Honeywell T10+ Pro Smart Thermostat.
6.1 No Power to Thermostat
- Check Circuit Breaker: Ensure the circuit breaker for your HVAC system is in the "On" position.
- Verify Wiring: Double-check all wiring connections at the thermostat base and HVAC system for secure contact.
6.2 Incorrect Temperature Readings
- Sensor Placement: Ensure the thermostat and indoor air sensors are not in direct sunlight, near heat sources, or in drafts.
- Sensor Pairing: Verify that all indoor air sensors are properly paired and communicating with the main thermostat.
6.3 HVAC System Not Responding
- System Mode: Confirm the thermostat is set to the correct system mode (Heat, Cool, Auto).
- Temperature Setting: Ensure the desired temperature is set above the current room temperature for heating, or below for cooling.
- Professional Assistance: If the issue persists, contact a qualified HVAC technician.
6.4 Connectivity Issues (RedLINK, Wi-Fi)
- Router: Ensure your Wi-Fi router is functioning correctly and within range.
- Thermostat Wi-Fi: Check the thermostat's settings to ensure it is connected to your home Wi-Fi network.
- RedLINK Signal: Ensure indoor air sensors are within range of the thermostat for RedLINK communication.
7. Specifications
| Attribute | Detail |
|---|---|
| Brand | Honeywell |
| Model Name | T10+ |
| Model Number | THX321WFS3001W |
| Controller Type | Touchscreen, Amazon Alexa, Google Assistant |
| Color | White |
| Temperature Control Type | Smart/Remote |
| Connectivity Technology | RedLINK 3.0 |
| Voltage | 24 Volts (AC) |
| Display Type | Touchscreen |
| Control Method | Touch |
| UPC | 194159012431 |
| Product Dimensions | 6 x 2.5 x 5.5 inches |
| Item Weight | 14.4 ounces |
| Date First Available | July 12, 2024 |
8. Warranty and Support
For warranty information and technical support, please refer to the official Honeywell documentation included with your product or visit the Honeywell support website. Keep your purchase receipt for warranty claims.
Online Support: www.honeywellhome.com
Contact: Refer to your product packaging or the Honeywell website for specific contact numbers for customer service.





