Quick Summary
The HTW-WF01-FC-4NE is a room thermostat designed for four-pipe fan coil unit applications with independent heating and cooling control. It manages multi-speed fan operation and controls two wired motorized valves for heating and cooling, supporting stable temperature regulation in both operating modes. The room thermostat supports Modbus communication for system integration and allows temperature sensing through either an internal sensor or an external sensor.
This page explains how the room thermostat works within a four-pipe FCU system, why its control logic matters for engineering applications, how to confirm technical specifications for projects, and what customization options may be discussed for specific installations.
Key Functional Highlights
(01) Independent Heating and Cooling Valve Control
In four-pipe fan coil systems(2 Pipe click here), heating and cooling circuits operate independently and require accurate valve coordination. This room thermostat controls two wired motorized valves separately, ensuring correct mode operation and avoiding unnecessary energy consumption caused by conflicting signals.
(02) Fan Coil Unit Control with Defined Electrical Limits
The room thermostat controls fan coil unit fans using dedicated relay outputs with clearly defined current ratings. This design supports common FCU fan motors and helps installers verify electrical compatibility, reducing commissioning risks and improving long-term operational stability.
(03) Modbus Communication for Centralized Monitoring
With built-in Modbus communication, the room thermostat can be integrated into building management systems for centralized monitoring and parameter adjustment. Local room control logic remains unchanged, ensuring reliable operation even if network communication is interrupted.
(04) External Sensor Support for Accurate Temperature Reading
In installations where wall-mounted temperature readings may be affected by airflow or heat sources, the room thermostat supports an external sensor. This allows engineers to optimize sensor placement and improve control accuracy based on real room conditions.
Details
Specifications
| Power Supply | 110 VAC (+/−10%) or 220 VAC (+10%, −15%) |
| Frequency | 50 / 60 Hz |
| Control Application | Heating and cooling, four-pipe fan coil system |
| Accuracy | ±1°C at 21°C |
| Fan Relay Load | 5A (3A inductive) |
| Valve Relay Load | 3A (1A inductive) |
| Setpoint Range | 5–35°C |
| Installation | 86×86 mm junction box or US 2×4 in box |
Display
Wiring
Project Fit & Customization
This room thermostat is intended for four-pipe fan coil unit systems that require independent control of heating and cooling valves. It is not suitable for two-pipe systems, applications without wired motorized valves, or projects that require purely standalone operation without system coordination. It should also not be used to control loads exceeding the specified relay ratings or in environments requiring protection levels higher than IP20.
OEM and ODM options can be discussed based on project scale and technical feasibility. Typical customization includes OEM logo printing, housing color customization, and selected function or interface adjustments. All customization is evaluated collaboratively to ensure compatibility with the original control architecture.
Certifications 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
Can this room thermostat be used in a two-pipe fan coil system?
No. This model is designed specifically for four-pipe systems with separate heating and cooling valves.
Does the room thermostat support connection to a building management system?
Yes. Modbus communication allows integration with centralized monitoring and control systems.
Can an external temperature sensor be used instead of the built-in sensor?
Yes. The room thermostat supports an external sensor to improve temperature measurement accuracy.
What is the minimum order quantity and are samples available?
Samples are supported. The typical minimum order quantity is 300 units, with smaller trial quantities open for discussion.
Related Thermostat Models
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For four-pipe fan coil projects, a room thermostat should be selected by system structure, heating and cooling valve outputs, fan relay load, sensor position, and Modbus integration requirements. The HTW-WF01-FC-4NE is suitable for projects that need independent heating and cooling control, multi-speed fan operation, external sensor support, and BMS-ready communication. For OEM buyers, contractors, and system integrators, confirming wiring, voltage, valve load, sensor use, communication needs, and project quantity before ordering will help reduce installation and commissioning risks.
If you are selecting a room thermostat for a four-pipe fan coil project, contact us to discuss system requirements, wiring conditions, and integration considerations.
