3KW Mini Electric Water Heater Thermostat for Bathtub SPA Hot Tub & Swimming Pool – Precision Thermostat

Compact 3KW mini electric thermostat for use with bathtubs, spas, hot tubs, massage baths and small pool heaters. Built-in precision temperature control includes an ultra-high temperature protection switch to prevent overheating. Initial setup and verification: After installation and basic safety checks, fill the tub to the correct water level and power the system. The unit will run an automatic self-check and heat until the thermostat reaches its maximum setting and the display lights go out. At that point, confirm the water temperature with an accurate thermometer — it should read 40 °C. Normal operation: The thermostat works fully automatically. Rotate the control clockwise to start heating; an indicator light shows when heating is active. Once the preset temperature is reached, the unit maintains that temperature. Temperature limits and heating rate: The thermostat is designed to maintain temperatures not exceeding 40 °C (104 °F). When starting with cold water, expect a temperature rise of approximately 6 ~ 8 °C/h. Automatic cycling and safety cutoff: The heater will reach the set temperature and then stop; when the water cools by a few degrees, the thermostat will automatically restart heating. If the water temperature goes over 49 °C, the ultra-high temperature switch will trip and cut power to the unit for safety.