Quick Summary
The HTW-31-F10-2B/4B BACnet thermostat is designed for FCU systems in commercial buildings. It controls a 3-speed fan and on/off valves for heating and cooling. The 2-pipe or 4-pipe versions support different system layouts. BACnet MS/TP communication allows stable integration with building management systems.
This page explains how it works within FCU control systems. It also outlines control logic, key parameters, and installation considerations. Typical questions and project concerns are addressed with practical answers. Options for system matching and customisation can also be discussed for different projects.
Key Functional Highlights
(This section introduces the main control functions and their engineering value in the FCU system.)
(01) 3-speed fan control
The thermostat supports low, medium, and high fan speeds for different load conditions. This allows better comfort control in changing room environments. Stable fan switching improves long-term reliability in FCU systems.
(02) 2/4 pipe (on/off valve control)
This BACnet thermostat is available for both 2-pipe and 4-pipe FCU systems. The 2-pipe version switches between heating and cooling by system mode. The 4-pipe version controls separate heating and cooling valves independently. This flexibility supports different building designs and retrofit requirements.
(03) BACnet MS/TP communication
BACnet MS/TP enables communication with a building management system over RS485. The thermostat can share temperature data, status, and control commands. This supports central monitoring and coordinated system operation. It improves maintenance efficiency across large fcu installations.
If one prefers WiFi than BACnet, one may consider this model instead (please click → HTW-31-F10-2W).
(04) White or Black display options
The thermostat is available with a white positive display or a black negative display. This allows a better visual fit with different interior styles. The display remains clear under different lighting conditions. It helps improve usability for daily operation and system checks.
Product Design and Display
(This section shows the thermostat appearance, screen interface, or installation dimensions of this specific model.)


Technical Specifications
(This section lists the key technical parameters relevant to this thermostat model.)
| Parameter | Value |
|---|---|
| Power Supply | 220Vac, 50/60Hz |
| Fan Relay Load | 5A |
| Built-in Sensor | NTC3950, 10K |
| Temperature Accuracy | ±0.5°C |
| Set-Point Range | 5~35°C |
| Installation | 86x86mm or EU round box |
| Warranty | 2 Years |
Wiring Diagram
(This section provides the wiring diagram for this thermostat in the relevant HVAC control system.)

Model Code Guide
(This section explains what configuration the model code refers to.)
| HTW-F10-xx | xx stands for |
| 2/4 | 2 for 2-pipe on/off; 4 for 4-pipe on/off system |
| M | Modulating valve control |
| W | Wi-Fi |
| N/B | N for Modbus; B for BACnet |
| K | K for Keycard |
| Example HTW-F10-2W stands for a 3-speed fan, 2-pipe system with on/off valve control, and WiFi communication. Most sub-models are ready-made. Kindly contact us to confirm availability. | |
Project Fit & Customisation
(This section describes project suitability, system limitations, and available customisation options.)
This BACnet thermostat is not suitable for systems requiring modulating valve control. It does not support the EC fan with 0–10V signal control. Standalone use without BMS may not use its full value.
Despite these limitations mentioned above, we can support ODM function changes. Communication protocol and control logic can be adjusted if needed. Display type and sensor options can also be discussed for projects.
OEM customisation is also supported for branding and appearance. Logo printing, label updates, and packaging changes can be arranged. Colour options can be adjusted to match project needs.
Certificates and Compliance
(This thermostat complies with European market requirements and is supported by certifications such as CE, RoHS, LVD test reports, EMC test reports, etc)

Exhibition Moments
(Our team regularly participates in international HVAC exhibitions such as Febrava in Brazil, The Big 5 in Dubai, and ISK-SODEX in Turkey, etc.)

Frequently Asked Questions
Q1: Can this BACnet thermostat work with any BMS system?
It supports BACnet MS/TP over RS485 communication. Compatibility depends on BMS setup and protocol matching. Proper settings are needed during commissioning.
Q2: How does the thermostat control heating and cooling?
In 2-pipe systems, heating or cooling depends on system changeover. In 4-pipe systems, valves are controlled separately. This gives more stable room temperature control.
Q3: Can an external sensor be used with this model?
This model does not support an external sensor by default. If needed, we can customise this function for your project. Please contact us to check the options and confirm details.
Q4: What data can be read through BACnet communication?
Temperature, set-point, and running status can be shared with the BMS. Commands can also be sent from the system. This helps central monitoring and control.
Q5: What is the MOQ, and can we order samples?
We can provide samples for testing before bulk order. The usual MOQ is around 300 units. Smaller trial orders, such as 100 units, can be discussed.
Q6: How to place an order and arrange shipment?
Please contact us to confirm your needs and model details. We will then provide a PI for your order. Payment can be made by TT, PayPal, or Visa, with EXW, FOB, or DAP terms.
Q7: What is the production lead time?
Standard samples are usually ready within 7 days. Custom models need about 3 to 5 weeks. Bulk orders around 300 units usually take about one month.
Q8: How will the products be delivered?
We usually suggest courier delivery like DHL, FedEx, or UPS, which takes about 7 days. Air freight is also available with similar timing. Sea freight takes about one month or more.
Need Help Choosing the Right Model?
If you are unsure about system matching or communication needs, please feel free to contact us. We can help review your project and suggest a suitable model.
Related Thermostat Models
For more details, please click here directly: Wi-Fi Thermostats | Modbus Thermostats | BACnet Thermostats
Final Note
In fcu projects, stable temperature control and system coordination are important. This BACnet thermostat manages fan and valve operation with clear logic. It supports central monitoring and helps improve long-term system operation.







