model XY-FB needs to be connected to a faucet for use. Temperature is controlled by faucet(water flow). It will start working automatically when you open faucet, and turn off automatically when you close faucet.This model is without any adjustable buttons for turning on/off and temperature. Temperature depends on water flow. You can control faucet to control temperature, or just let the angle valve control a stable water flow in order to get a stable temperature. Please kindly note bigger water flow makes lower temperature,but smaller water flow makes higher temperature.