Quick Summary
HTW-EW002-WG is a split thermostat for fan coil unit systems using a separate wall thermostat and relay module. It controls 3-speed fan or EC fan operation, 2-pipe or 4-pipe systems, and on/off or modulating valves. It supports heating and cooling control, external sensor input, keycard, window card, and Modbus communication.
This page explains how the fcu controller works in real projects, why each function matters, and what should be checked before selection. It also covers technical parameters, wiring confirmation, common project limits, customization options, compliance, FAQ, and model support for OEM or engineering use.

Key Functional Highlights
(This section introduces the main split thermostat control functions and their engineering value in FCU projects.)
(01) Wide Power Supply Range
The 100~250VAC power input helps simplify project matching. It can suit many hotel, office, and apartment FCU projects. This reduces wrong voltage selection during procurement and site preparation.
(02) Split Thermostat Design
The thermostat and relay module are installed separately. They communicate through 3 wires, with a distance up to 50 metres. This helps keep relay switching noise away from the room area.
(03) 3-Speed Fan and EC Fan Control
This fcu controller can support traditional 3-speed fan control. It can also work with EC fan control when required. This makes the model useful for both standard and energy-saving FCU designs.
(04) 2-Pipe and 4-Pipe Valve Control
The split thermostat supports 2-pipe and 4-pipe FCU systems. Valve control can be configured for on/off or modulating output. This gives projects more flexibility when valve types differ by site.
(05) External Sensor Function
The external sensor helps read temperature from a better position. This is useful when the thermostat location is affected by sunlight or airflow. It can improve comfort control and reduce wrong temperature response.
(06) Keycard and Window Card Input
Keycard input helps reduce energy use in hotel rooms. Window card input can stop or limit operation when windows are open. These functions support better facility management and lower unnecessary running time.
(07) Modbus Communication
Modbus allows the fcu controller to exchange basic control data with a central system. This can support monitoring, setting adjustment, and project-level management. It is useful when many rooms need central supervision.
This WG version supports more Modbus addresses. Please feel free to contact us directly for the detailed protocol. If a smaller number of addresses is sufficient, this version may also be suitable (please click → HTW-EW002).
Product Design and Display
(This section shows the split thermostat appearance, screen interface, and installation details of this specific model.)


Technical Specifications
(This section lists the key technical parameters relevant to this fcu controller model.)
| Parameter | Value |
|---|---|
| Power Supply | 100~250VAC, 50/60Hz |
| Current Load | 3-speed fan relay 5A; 3A inductive |
| Built-in Sensor | NTC3950, 10K |
| Temperature Accuracy | ±0.5°C or ±1℉ |
| Set-Point Range | 5~35°C |
| Protection Class | IP20 |
| Warranty | 2 years |
| Installation | Thermostat: EU round box or 86×86mm box; Relay: DIN rail |
Wiring Diagram
(This section provides the wiring diagram for this split thermostat in the relevant HVAC control system.)

Project Fit & Customization
(This section describes fcu controller project suitability, system limits, and available customization options.)
HTW-EW002 is not suitable for simple projects that only need a basic wall thermostat. It is also not the best choice when there is no space for a DIN rail relay module. For wireless-only rooms, it does not replace Wi-Fi, Zigbee, or app control unless these functions are added separately.
Despite these limits, we can discuss function customization based on the project. For example, Wi-Fi, special control logic, display changes, output adjustment, or communication mapping may be considered. Custom functions need review by our engineering team before confirmation.
OEM support is also available for project orders. We can support logo printing, colour discussion, label design, packaging, and model naming. Please feel free to get in touch with us if the project needs a stable split thermostat supplier with practical OEM support.
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: What type of FCU system can HTW-EW002 control?
HTW-EW002 can work with 2-pipe and 4-pipe FCU systems. It supports heating and cooling control, depending on system design. Buyers should confirm valve type before ordering.
Q2: Why use a split thermostat instead of a normal wall thermostat?
A split design keeps the relay module away from the room panel. This helps reduce switching noise in quiet rooms. It is useful for hotels, offices, and comfort-focused projects.
Q3: Can this model control both 3-speed fans and EC fans?
Yes, this fcu controller can support 3-speed fan and EC fan control. The exact output configuration should be confirmed before production. This avoids mismatch with the FCU motor type.
Q4: Does HTW-EW002 support BMS integration?
Yes, Modbus can support connection with a central control system. The register map and required control points should be confirmed early. This helps the engineering team match the project logic.
Q5: What is the MOQ, and can we order samples?
We support sample orders for project checking. The usual MOQ is 300 pieces. Smaller trial quantities, such as 100 pieces, can also be discussed.
Q6: How can we place an order and arrange payment?
Please get in touch with us to confirm the project requirements first. We can then provide a PI for confirmation. Payment can support TT, PayPal, Visa, and terms such as EXW, FOB, or DAP.
Q7: How long does it take to prepare the products?
Non-customized samples can usually be sent within 7 days. Customized projects need function review, software adjustment, and testing. This usually takes 3~5 weeks, while 300 pieces often need about one month.
Q8: How do you arrange shipping?
For samples, express delivery is usually recommended. FedEx, DHL, or UPS door-to-door delivery often takes about 7 days. Air freight may take about 7 days, while sea freight usually needs one month or more.
Need Help Choosing the Right Model?
Please feel free to get in touch with us with your FCU wiring, valve type, and control needs. We can help check the suitable model.
Related Thermostat Models
For more details, please click here directly: Wi-Fi Thermostats | Modbus Thermostats | BACnet Thermostats
Final Note
FCU projects usually need stable room control, quiet operation, and clear system matching. HTW-EW002 works as a fcu controller for fan, valve, and communication control. Its split structure supports easier maintenance, central monitoring, and smoother facility management.







