Quick Summary
The HTW-FC09-4N digital thermostat is designed for fan coil unit control in typical HVAC rooms. It manages a 3-speed fan and on/off valves in 2-pipe or 4-pipe systems. The controller regulates heating or cooling according to the room temperature and set-point. RS485 Modbus allows central monitoring in building control systems.
This page explains how the digital thermostat works in FCU control projects. It outlines the control logic, key functions, and important parameters. Typical questions about installation, communication, and model selection are also discussed. Customisation possibilities for projects may also be considered.
Key Functional Highlights
(This section explains the core control functions and their practical value.)
(01) 3-speed fan control
Three selectable fan speeds allow airflow adjustment according to room demand. This helps balance comfort and noise. In FCU installations, stable fan control improves airflow distribution and keeps the room temperature closer to the set-point.
(02) 2/4-pipe on/off valve control
The controller supports both 2-pipe and 4-pipe FCU systems. Heating and cooling valves switch according to temperature demand. This flexible design allows one digital thermostat to suit different fan coil system layouts.
(03) RS485 Modbus communication
RS485 Modbus enables communication with building management systems. Central software can read temperature and device status. This helps facility teams monitor rooms and maintain stable HVAC operation across projects.
If other features are needed, such as a keycard, one may refer to this model instead (click → HTW-FC08-4KN), which also supports Modbus and on/off valve control.
(04) VA screen with negative display
The VA display provides clear white characters on a dark background. This improves visibility in low-light environments such as hotel rooms. Operators can quickly check temperature and system status from the screen.
(05) Power failure memory function
The thermostat stores settings before a power interruption occurs. After power returns, the controller restores the previous configuration automatically. This prevents system reset issues and reduces manual setup work.
Display
(This section shows the product’s dimensions and the interface layout.)
Specifications
(This section lists the key parameters for reference and project confirmation.)
| Parameter | Value |
|---|---|
| Power Supply | 95–240Vac, 50/60Hz |
| Fan/Valve Relay Load | Fan 5A; Valve 5A |
| Built-in Sensor | NTC3950, 10K |
| Temperature Accuracy | ±0.5°C |
| Set-Point Range | 5–35°C |
| Installation | EU round box or 86×86mm box |
| Warranty | 2 Year |
Wiring
(This section provides the wiring reference diagram for correct installation.)
Project Fit & Customisation
(This section explains where the product can be used, its limits, and OEM/ODM options.)
This digital thermostat is not suitable for systems requiring wireless control. It does not support mobile applications or Wi-Fi networking. Projects needing advanced graphical interfaces or EC fan motors may require different controller types.
Despite these limitations mentioned above, ODM function adjustments can be discussed. Communication options such as Wi-Fi or BACnet may be evaluated for specific projects. Sensor options, control logic, or firmware adjustments can also be considered after technical confirmation.
OEM cooperation is also supported for project deployment. Logo printing, colour variations, and packaging labels may be customised. Private labels and product markings can be arranged for distributor or brand projects.
Certifications
Exhibition Moments
Frequently Asked Questions
Q1. Can this digital thermostat control both heating and cooling in FCU systems?
Yes. The controller supports both 2-pipe and 4-pipe fan coil systems. It switches valves according to temperature demand. This allows heating or cooling control in typical room HVAC applications.
Q2. Can the thermostat communicate with a building management system?
Yes. RS485 Modbus communication allows integration with many building management platforms. The central system can read temperature and device status. This helps facility teams manage multiple rooms.
Q3. Does the thermostat support an external temperature sensor?
No. The controller includes a built-in NTC temperature sensor. It measures room temperature near the installation location. Correct placement on the wall improves measurement accuracy.
Q4. How do I choose the correct thermostat model for a project?
Model selection depends on fan type, pipe system, and communication requirements. Some projects need standalone control only. Others may require Modbus communication for central monitoring.
Q5. What is the minimum order quantity, and can I get samples?
Yes, samples are available for testing and evaluation. The typical minimum order quantity is about 300 units. Smaller trial quantities such as 100 units may also be discussed.
Q6. How can I place an order and arrange payment?
Please contact us to confirm the model and project requirements. A proforma invoice will then be issued. Payment methods include TT, PayPal, and Visa. Shipping terms may include EXW, FOB, or DAP.
Q7. How long does product preparation usually take?
Standard samples are usually shipped within seven days. Customised models require program adjustment and evaluation. This process normally takes three to five weeks depending on functions. Bulk orders around 300 units usually need about one month.
Q8. What shipping options are available for delivery?
Express courier such as DHL, FedEx, or UPS is often recommended. Delivery usually takes about seven days door-to-door. Air freight may take around seven days, while sea freight may require about one month.
Need Support?
If you are evaluating a digital thermostat for an FCU project, feel free to contact us. Our team can help review system compatibility and suggest suitable configuration options. To find out others, please click (Modbus thermostats).
Final Note
In many HVAC projects, room-level control and system visibility are both important. The HTW-FC09-4N thermostat regulates fan coil airflow and valve switching based on room temperature demand. Modbus communication also allows central monitoring, helping facility teams manage multiple rooms more consistently.
