Quick Summary
HTW-EW002 is a Modbus HVAC thermostat designed for fan coil unit control in hotel, apartment, and light commercial rooms. It uses a split structure with a wall thermostat and a DIN rail relay module. It can control 3-speed fans, EC fans, 2-pipe or 4-pipe systems, and configurable valve outputs.
This page explains the working value of each function, the FCU control logic, technical checks, wiring reference, project limits, and customization options. It also helps engineers, OEM buyers, and system integrators judge whether this model fits their room control project.
Key Functional Highlights
(This section introduces the main control functions and engineering value of this Modbus HVAC thermostat in FCU applications.)
(01) Wide Power Supply Range
The 100~250VAC power input helps simplify model selection across different markets. It reduces the risk of choosing the wrong voltage version. This is useful for hotel and apartment projects with mixed site conditions.
(02) Split Design for Quieter Rooms
HTW-EW002 separates the wall panel from the relay module. The two parts communicate through 3 wires, up to 50 metres. This helps keep relay switching noise away from guest rooms or quiet offices.
(03) 3-Speed Fan Control and EC Fan Support
The thermostat can control standard 3-speed fan coil units. This suits many traditional FCU systems used in hotels and residential buildings. It helps maintain simple and reliable room airflow control. It also supports EC fan control when required. EC fan systems are often used for better energy performance. Buyers should confirm the required output type before ordering.
(04) 2-Pipe and 4-Pipe Compatibility
HTW-EW002 can be configured for 2-pipe or 4-pipe FCU systems. This allows one platform to support cooling-only, heating-cooling, or seasonal changeover projects. It helps reduce model confusion across different room types.
(05) On/Off or Modulating Valve Control
The valve control can be configured for on/off or modulating applications. This makes the model suitable for different valve strategies. It is important to confirm valve type, voltage, and control signal before production.
(06) External Sensor Function
This Modbus HVAC thermostat supports an external sensor for better temperature reading. It helps when the wall position is affected by sunlight, airflow, or heat sources. A better sensor position can improve comfort and control stability.
(07) Keycard and Window Card Input
Keycard input helps reduce energy use when the room is unoccupied. Window card input can stop or limit operation when windows are open. These functions are useful for hotel energy management and daily operation.
(08) Modbus Communication
Modbus allows the thermostat to connect with a central control or BMS system. It can support remote monitoring, setting adjustment, and room status checking. This is useful when many rooms need central facility management.
This version has fewer Modbus addresses, which is normally sufficient, but if one is interested in more features, please check this version (HTW-EW002-WG) instead and feel free to contact us for the detailed protocol.
Product Design and Display
(This section shows the appearance, screen interface, and installation details of this Modbus HVAC thermostat model.)
Technical Specifications
(This section lists the key technical parameters relevant to this hvac thermostat.)
| 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 Modbus thermostat in the relevant FCU control system.)
Project Fit & Customization
(This section describes project suitability, system limits, and customization options for this model.)
HTW-EW002 is not the best choice for very simple rooms that only need basic on/off temperature control. It also needs installation space for the separate relay module. If the project requires direct app control, Zigbee control, or Wi-Fi control, those functions must be discussed separately.
Despite these limits, we can discuss function customization based on project needs. For example, Wi-Fi, display changes, special logic, output adjustment, or Modbus point mapping may be reviewed. Custom functions need engineering confirmation, so we do not suggest confirming them only by catalogue information.
OEM support is available for suitable 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 you need a Modbus HVAC thermostat for a specific FCU project.
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 fan coil systems. It supports heating and cooling control, depending on the system design. Buyers should confirm fan type and valve type before ordering.
Q2: Why choose a split design for this model?
The split design keeps the relay module separate from the room panel. This helps reduce relay noise inside the room. It is useful for hotels, quiet offices, and comfort-focused projects.
Q3: Can this Modbus HVAC thermostat work with EC fans?
Yes, it can support EC fan control when the correct output is configured. It can also support traditional 3-speed fan control. The required fan logic should be confirmed before production.
Q4: Can HTW-EW002 connect to a BMS system?
Yes, Modbus communication can support connection with a BMS or central control system. The register map should be checked before project confirmation. This helps match the required monitoring and control points.
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 feel free to get in touch with us to confirm your requirements first. We can then provide a PI for checking. 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 around 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 quiet room control, stable operation, and clear system matching. HTW-EW002 works as a Modbus HVAC thermostat for fan, valve, and central communication control. Its split structure helps support easier maintenance, room comfort, and facility management.
