3KW Mini Electric Water Heater Thermostat for Swimming Pool, Bathtub, Spa & Massage Hot Tub — Efficient Heating

Initial setup and safety: After installation, perform safety checks and confirm the thermostat works correctly. The unit includes an ultra-high temperature protection switch to prevent overheating. For first use, fill the tub to the proper level and start the system so it can run an automatic check; allow it to heat at the maximum setting until the display lights go out and the temperature stabilizes. Use an accurate thermometer to verify the water temperature should be 40 °C. Automated control: The thermostat operates fully automatically. Turn clockwise to switch on heating — the indicator light will illuminate. When the preset temperature is reached, the heater will maintain that temperature. The thermostat is designed to keep temperature within a limit not exceeding 40 °C (104 °F). Heating behavior and protection: When starting with cold water, expect a rise in temperature of approximately 6 ~ 8 °C/h. The thermostat cycles automatically: it heats up to the preset temperature, then stops until the water cools a few degrees, at which point it restarts. If the temperature goes over 49 °C, the ultra-high temperature switch will trip and cut power.