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

Initial setup and safety check: after installation, perform a safety inspection and verify the thermostat functions correctly. Fill the tub to the appropriate level and start the unit — it will run an automatic self-check and operate until the thermostat stabilizes at its highest setting and the display lights go out. Measure the water temperature with an accurate thermometer; it should read 40 °C at this point. Operation and control: the thermostat is fully automatic. Turning the control clockwise switches heating on and lights the indicator; when the preset temperature is reached the unit holds that temperature. Temperature range and heating rate: the thermostat is designed to keep water at or below 40 °C (104 °F). If the system is started with cold water, the water temperature will rise at approximately 6 ~ 8 °C / h. Automatic cycling: once the preset temperature is attained the thermostat stops heating and will automatically restart when the temperature falls by a few degrees. High-temperature protection: if the water exceeds ultra-high temperature (over 49 °C) the dedicated high-temperature switch will trip and cut power to prevent overheating and protect users.