Quick Summary
The HTW-FC09-3KDMEN modbus thermostat is designed for fan coil ac system control. It manages a 3-speed fan and supports 2-pipe valve control. Both on/off and modulating control are available. It works in heating and cooling modes with stable control logic.
This page covers its control logic, function meaning, and key parameters. It also includes wiring guidance and typical project questions. Customisation options are outlined for practical project use.
Key Functional Highlights
(This section introduces the main control functions and their engineering value in the ac system.)
(01) 3-speed fan control
Three fan speeds allow flexible airflow adjustment during operation. This helps balance comfort and noise levels in different rooms. It also improves system stability by matching airflow with real cooling or heating demand.
(02) 2-pipe valve control (on/off or modulating)
This modbus thermostat supports both on/off and modulating valve control. It fits common 2-pipe ac system layouts used in many projects. This flexibility helps reduce design changes during project deployment.
If a thermostat with 24V output for the modulating valve is preferred, this model may be considered (please click → HTW-FC09-FVMN-24K).
(03) RS485 Modbus communication
RS485 Modbus allows connection with a BMS for central control. We can monitor room status and adjust settings remotely. This improves operation efficiency and reduces manual maintenance work.
(04) External sensor support
An external sensor provides additional temperature input when required. It helps improve control accuracy in larger or complex rooms. This ensures more stable performance where built-in sensing is not sufficient.
(05) 2 digital inputs + 1 analogue input
Multiple inputs allow flexible integration with field signals. Digital inputs can connect door contacts or occupancy signals. The analogue input supports extended control logic in more complex ac system projects.
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 | 95~240Vac, 50/60Hz |
| Current Load | Fan Relay 5A |
| Built-in Sensor | NTC3950, 10K |
| Temperature Accuracy | ±0.5°C |
| Set-Point Range | 5~35°C |
| Installation | Standard 86x86mm Box |
| Warranty | 2 Year |
| Control Type | 3-speed fan + 2-pipe |
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-FC09-xxx | xx stands for |
| FVM | 0-10V EC fan + Modulating valve |
| 24 | with 24V output for 0-10V valve |
| WF | Wi-Fi |
| ZB | Zigbee communication |
| K/S | K = Keycard; S = External sensor |
| Example HTW-FC09-FVMN-24K: it stands for the model with EC fan, 0-10V valve control, a built-in transformer featuring 24VDC output, Modbus and Keycard. For more details, kindly contact us to confirm availability. | |
Project Fit & Customization
(This section describes project suitability, system limitations, and available customization options.)
This modbus thermostat is not suitable for VRF or heat pump systems with complex logic. It does not support standalone wireless control without additional modules. It also requires correct RS485 configuration for stable ac system communication.
Despite these limitations mentioned above, we can support function customisation based on project needs. Communication options such as Wi-Fi or BACnet can be discussed. Input logic and control behaviour can also be adjusted within practical limits.
We also support OEM customisation for project supply. This includes logo printing, housing colour, and label design. Packaging and basic interface adjustments can be arranged based on requirements.
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 modbus thermostat connect to a BMS system?
Yes, it supports RS485 Modbus communication for BMS integration, and we can monitor room status or adjust settings remotely, which helps central management and reduces on-site work.
Q2: Does it support both heating and cooling control?
Yes, it works in both heating and cooling modes, and the control logic switches based on system demand, which makes it suitable for standard ac system layouts.
Q3: When should an external sensor be used?
An external sensor is useful in large or uneven rooms, and it improves temperature accuracy beyond the built-in sensor, helping maintain more stable control.
Q4: Can the inputs be used for hotel or occupancy control?
Yes, digital inputs can connect door or occupancy signals, and this supports energy saving logic in projects, while the analogue input allows further control expansion.
Q5: What is the MOQ and is sample available?
Yes, we support sample orders for testing, and MOQ is usually 300 units, but smaller batches such as 100 units can be discussed for trial use.
Q6: How can we place an order?
We can confirm requirements first and then provide a PI, and we support TT, PayPal, and Visa, while EXW, FOB, and DAP terms are available.
Q7: How long does production take?
Non-custom samples are usually shipped within 7 days, while customised product take about 3–5 weeks depending on functions, and bulk orders such as 300 units normally require one month.
Q8: What shipping methods are available?
We usually recommend courier delivery which takes about 7 days to door, while air freight takes around 7 days and sea freight takes about one month depending on conditions.
Need Help Choosing the Right Model?
If we are working on an ac system project, we can discuss together and help confirm a suitable modbus thermostat based on the application.
Related Thermostat Models
For more details, please click here directly: Wi-Fi Thermostats | Modbus Thermostats | BACnet Thermostats
Final Note
Reliable control is important in HVAC projects with changing room demand. This modbus thermostat manages fan coil operation and supports system communication. It helps maintain stable performance and supports efficient facility management across the ac system.
