Features:The pump automatically starts to work when the water temperature reaches the set temperature,the pump automatically stops working when water temperature is below the set temperature.Specification:Voltage: 220VPower consumption: 3WTemperature range: 0 to 100 Hysteresis temperature: 5 CelsiusTemperature switch deviation: 2Ambient temperature: -5 to 50CelsiusSize:122mm*90mm*46mm(L*W*H)External sensor: Lead length 1m, rubber Rerong package.Measuring range :5-100 degreesCurrent: 5AError: 2 Installation method:Firstly, thermostat fixed at 1m far away from the boiler , the temperature probe stick to the highest point in the boiler water temperature, pump power connect with the thermostat,and please also connect thermostat with the main power supply.After that thermostat instructions lights up, thermostat can work.Adjust the temperature control knob to set the temperature you need.Precautions1.The temperature probe prohibit stick surface above 100 degrees, such as: the surface of the furnace chimney.2.The surface temperature of the boiler there is a certain difference in temperature with circulating water temperature, but does not affectthe pump automatically circulation.3.The power connections must be tightened, or does not work properly.4.Size for manual measurement, there may be a 0 to 2mm error, belongs to the normal phenomenon.Package Include:1x Thermostat Regulator with Sensor