All-in-one Design Smart Thermostat WiFi RS485 Modbus
HTW-FC24 Series thermostat is used indoors with fan coil systems. It senses temperature and controls the fan and valve, keeping the room comfortable.
Quick Summary
HTW-FC24-Altra is a fan coil smart thermostat for FCU projects that need flexible fan and valve control. It supports 3-speed fan control and EC fan control. It can work with 2-pipe or 4-pipe systems, including on/off valve control and modulating valve control under a suitable configuration.
This page explains how the model works in real HVAC projects, not only how it looks. It covers control value, system logic, key parameters, wiring confirmation, common project questions, and possible customisation. One may use it as an engineering guide before confirming a sample or order.
Key Functional Highlights
(This section introduces the main control functions and the value of this specific FCU smart thermostat.)
(1) 3-speed fan and 0-10V EC fan control
This model is useful when one project includes different fan coil requirements. Standard relay fan control suits many traditional FCU systems. EC fan control helps projects that need smoother airflow and better energy management. This can reduce model confusion during project selection.
(2) 2-pipe and 4-pipe system support
HTW-FC24-Altra can be configured for 2-pipe or 4-pipe fan coil systems. In a 2-pipe project, valve control can be on/off or modulating. In a 4-pipe system, on/off valve control is normally used. This helps match cooling, heating, or seasonal changeover needs.
(3) Fan coil plus auxiliary water heating
Some rooms need fan coil cooling and extra water heating control. This model can support that mixed system logic when the project is designed correctly. It is useful for apartments, hotels, and light commercial spaces.
(4) External sensor or keycard option
An external sensor helps when the wall temperature is not reliable. A keycard input is useful for hotel rooms and serviced apartments. It can support better energy control when guests leave the room. These options should be confirmed before production.
(5) RS485 communication and Wi-Fi app control
This model can support RS485 communication for building-side monitoring. Modbus is useful when a project needs central data reading or basic BMS connection. App control can also be added through WiFi when remote operation is needed. We suggest confirming which side controls the room first.
If the project does not require the Wi-Fi feature, one may refer to this model instead (HTW-FC24-4KEN), which features Modbus, 2/4-pipe and External sensor or keycard option.
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 WiFi thermostat model.)
| Parameter | Value |
|---|---|
| Power Supply | 24V, or 100~250VAC, 50/60Hz |
| Current Load | 3 Speed Fan Relay: 5A, 3A inductive |
| Sensor Support | Built-in Sensor(NTC3950, 10K), External Sensor, Humidity Sensor |
| Temperature Accuracy | ±0.5°C or ±1℉ |
| Set-Point Range | 5~35°C |
| Warranty | 2 Year |
Wiring Diagram
(This section provides the wiring diagram for this Modbus thermostat in the relevant HVAC control system.)
Project Fit & Customisation
(This section describes project suitability, system limits, and available customisation options for this smart thermostat.)
This model is not suitable for every HVAC project. It should not be used for boiler-only heating, electric floor heating, or heat pump systems. It is also not the best choice when the project needs a different communication protocol like BACnet or Zigbee.
Based on project needs, we can discuss ODM function customisation within a clear technical scope. For example, keycard and external sensor can be changed from an either-or option to combined support. Modbus plus WiFi may also be adjusted to Zigbee or BACnet, and more fan speed options can be reviewed.
OEM customisation is also available for distributors, project suppliers, and brand partners. We can support logo printing, colour adjustment, front panel marking, labels, packaging, manuals, and model code rules. Please feel free to get in touch with us before confirming artwork or batch details.
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 HTW-FC24-Altra control both 3-speed fan and EC fan systems?
Yes, this model can be configured for both fan types. The correct version depends on the fan coil unit and wiring design. Please share the FCU diagram before sample confirmation.
Q2: Can this thermostat work with both 2-pipe and 4-pipe systems?
Yes, it can support 2-pipe and 4-pipe fan coil systems. The 2-pipe version may support on/off or modulating valve control. The 4-pipe version usually uses on/off valve control.
Q3: When should we use an external sensor?
An external sensor is useful when the wall position gives a wrong room reading. This may happen near doors, sunlight, or airflow. It helps improve comfort and control stability.
Q4: Is Modbus needed for every project?
No, Modbus is only needed when the project requires central monitoring or BMS connection. For simple apartments, local control or WiFi operation may be enough. We suggest checking the project management method first.
Q5: What is the MOQ, and do you support samples?
Yes, we support samples for testing before batch orders. The usual MOQ is 300 pieces. We can also discuss a smaller trial order, such as 100 pieces.
Q6: How can we place an order and arrange payment?
Please feel free to get in touch with us and confirm the project needs first. We will then provide a PI for checking. We support TT, PayPal, Visa, and terms such as EXW, FOB, and DAP.
Q7: How long does it take to prepare the products?
Non-custom samples can usually be sent within 7 days. Custom orders need project review, quantity checking, and programme adjustment. This usually takes 3–5 weeks, while 300 pieces often need about one month.
Q8: How do you ship the products?
For samples and urgent orders, we usually suggest courier delivery by FedEx, DHL, or UPS. Door-to-door delivery often takes about 7 days. Air shipment may take about 7 days, while sea shipment often needs over one month.
Need Help Choosing the Right Model?
Please feel free to get in touch with us. We can help check your FCU system, wiring, and project control needs.
Related Thermostat Models
For more details, please click here directly: Wi-Fi Thermostats | Modbus Thermostats | BACnet Thermostats
