8921A-RHLD-WIFI Hydronic Floor Heating Thermostat
Key Specifications
· Smart thermostat for hydronic (water) floor heating
· Linkage function (optional) · WiFi Tuya app (optional)
· 86×86×9mm (panel) · 135g
The 8921A-RHLD-WiFi is a WiFi hydronic floor heating thermostat designed for water-based underfloor heating systems. It supports Tuya App for remote operation and scheduling, optional linkage function, and Modbus RTU communication. For official protocol details, visit the Modbus Organization website.
Why Choose 8921A-RHLD-WIFI Hydronic Floor Heating Thermostat
· Linkage Function – Optional transceiver-based device-to-device automation (e.g., with AC or fresh air)
· WiFi Tuya App – Optional smart control via Tuya App for remote operation and scheduling
· Ultra-Slim Design – Only 9mm panel thickness for a sleek look
· Lightweight – 135g for easy installation
8921A-RHLD-WIFI Hydronic Floor Heating Thermostat Operation Functions
1. Core Control
– Valve Regulation: Controls hot water flow to radiators/floor pipes based on room temperature vs. setpoint.
– Heating ON when room temp < setpoint; Valve closes when temp ≥ setpoint.
2. Safety Protections
– High-Temp Cutoff (60°C): Auto-shuts valve if floor sensor ≥60°C.
– Sensor Failure: Displays Err/ E1/ E2 and locks heating output.
– Frost Protection: Forces heating ON if room temp < user-defined threshold (e.g., 5°C).
3. Programming Features
– 5+2/7-Day Scheduling: 6 time periods per day, separate settings for weekdays/weekends.
– Economy Mode: Pre-set energy-saving temperatures for unused periods.
4. Advanced Operations
– Key Lock**: Long-press ▲+▼ for 5s to enable/disable child lock.
– Floor Temp Display**: Long-press ▲ for 5s (dual-sensor models only).
– Advanced Settings**: Long-press Mode+Clock for 5s (off state) to configure:
– Frost protection threshold
– High-limit temperature (AL function)
– Sensor calibration
5. Technical Safeguards
– Low-Temp Auto-Start: Activates heating below user-set frost threshold.
– Post-Failure Recovery: Resumes operation only after fault clearance (e.g., sensor replacement).