The Underfloor Heating & Fan Coil Modbus Thermostat is a versatile and user-friendly device designed to control air to water heat pump systems.  With modbus protocal, users can easily control both heat pump and home heating system at the same time.  This air to water heat pump thermostat with two outputs for fan coil valve and underfloor water valve, it also workable for 3 fan speed fan coil or EC fan coil.   Item No.: FT-CS03 (2-in-1 Integrated Controller) Visual Interface: Attractive and Big HD Color LCD Display for intuitive operation. Operation Modes: Multiple modes control including Manual, Economy, and PRG (Programmable) Mode. System Compatibility: Supports Water Underfloor Heating or Cooling systems (3A relay). Dual-Season Support: Integrated Heat Mode & Cold Mode for year-round comfort. Ventilation Control: 3-speed fan control or advanced EC fan control compatible. Smart Scheduling: 7 days Fully Programmable (4 periods per day) to maximize energy efficiency. Building Automation: RS485/Modbus RTU protocol supported (Custom ODM service available). Wireless Connectivity: Tuya WiFi Remote Control via Smartphone App. User Convenience: Real-time Clock display and user-friendly interface. Safety & Protection: Built-in Frost protection (Param 56) and Child Lock functions. Certified Quality: Fully compliant with CE, ROHS, and RED international standards.