Quick Summary
HTW-EB-FC-2N Smart Modbus thermostat is designed for 2 pipe fan coil systems in heating and cooling applications. It controls a 3-speed fan relay and two-wire heating/cooling motorized valve. The thermostat operates under 95–240Vac power supply and supports Modbus communication for system integration and centralized control logic. Temperature sensing accuracy reaches ±0.5°C, ensuring stable environmental regulation in commercial and residential FCU projects.
This page explains how the Smart Modbus thermostat works in FCU systems, its control logic, technical specifications, installation conditions, and project-level customization possibilities.
Key Functional Highlights
(01) Modbus Communication for System Integration
The Smart Modbus thermostat supports Modbus protocol, enabling integration into building management systems. This allows centralized supervision, parameter adjustment, and multi-room control, improving project-level monitoring efficiency.
(02) Independent Fan and Valve Relay Output
Separate relay outputs for fan and motorized valve ensure precise control logic in 2 pipe systems. This structure avoids signal interference and improves operational stability during heating and cooling switching.
(03) Wide Voltage Adaptability
Operating within 95–240Vac range, the Smart Modbus thermostat adapts to various regional power standards. This reduces model differentiation across markets and simplifies project procurement planning.
(04) Stable Temperature Regulation Accuracy
With ±0.5°C accuracy, the Smart Modbus thermostat maintains consistent room conditions. This reduces temperature fluctuation, improves comfort consistency, and minimizes frequent relay cycling in FCU operation.
Details
Specifications
| Power Supply | 95–240Vac |
| Frequency | 50/60Hz |
| Temperature Accuracy | ±0.5°C or ±1℉ |
| Fan Relay Load | 5A (3A inductive) |
| Valve Relay Load | 3A (1A inductive) |
| Setpoint Range | 5–35°C |
| Power Consumption | <1.5W |
| Protection Class | IP20 |
Display
The Smart Modbus thermostat features a clear digital display showing room temperature and setpoint value. The display range covers 5–99°C. Housing material is PC + ABS fireproof structure, suitable for indoor wall mounting.
Wiring
The Smart Modbus thermostat supports 3-speed fan relay control and two-wire motorized valve output. Installation is compatible with EU or standard electric wall boxes. Proper separation between fan and valve terminals should be maintained during installation.
Project Fit & Customization
The Smart Modbus thermostat is not suitable for 4 pipe fan coil systems or applications requiring analog valve modulation (0–10V). It is designed for two-wire on/off motorized valves only. Projects requiring BACnet or advanced multi-protocol gateways may require external controllers. In addition, IP20 protection class means it should not be installed in high-humidity or outdoor environments.
Despite these limits mentioned above, function-level ODM customization can be discussed. Communication parameter adjustments, firmware logic modifications, display behavior changes, or temperature control algorithm tuning can be reviewed based on project requirements. Integration support with specific Modbus registers may also be evaluated.
OEM customization is also supported. Logo printing, housing color options (white or black), private label packaging, and label adjustments are available. Custom requirements can be confirmed before mass production.
Frequently Asked Questions
1. Is this Smart Modbus thermostat suitable for 4 pipe FCU systems?
This model is designed for 2 pipe systems controlling one two-wire motorized valve. We have another model(HTW-EB-FC-4N you can click on this link to read more details) which can support 4 pipe FCU systems.
2. Can it connect directly to a BMS system?
Yes, the Smart Modbus thermostat supports Modbus protocol for system integration.
3. What type of valve is supported?
It supports two-wire on/off motorized valves only.
4. What is the minimum order quantity? Are samples available?
Sample orders are supported. Standard MOQ is 300 units, but smaller trial quantities can be discussed.
5. How do we place an order?
Contact us to confirm requirements. We issue a proforma invoice. Payment supports TT, PayPal, Visa. Terms include EXW, FOB, DAP.
6. How is shipping arranged?
Express delivery takes about 7 days. Air freight similar. Sea freight usually takes over one month depending on destination.
If you are evaluating a Smart Modbus thermostat for a 2 pipe FCU project, contact us to discuss system requirements and integration details. We can assist with technical confirmation and application review.
