The invention discloses an electronic thermostatic valve, a water discharging method for the electronic thermostatic valve and a water heater with the electronic thermostatic valve. The electronic thermostatic valve comprises a valve body, a temperature adjusting part, an electromagnetic valve and a temperature sensor. The valve body is provided with a cold water inlet, a hot water inlet and a thermostatic water outlet. The temperature adjusting part is arranged in the valve body to adjust the outlet water temperature of the thermostatic water outlet. The electromagnetic valve is provided with a water inlet, a water outlet and a draining opening, and the water inlet is communicated with the thermostatic water outlet. The temperature sensor is used for detecting the temperature of the hot water inlet and controlling on and off of the water inlet, the water outlet and the draining opening of the electromagnetic valve according to the detected temperature. According to the electronic thermostatic valve in the embodiment, on and off of the water inlet, the water outlet and the draining opening of the electromagnetic valve are controlled through the temperature sensor, cold water which is at the temperature lower than the preset temperature and flows in from the hot water inlet and residual cold water at the water outlet can be drained through the draining opening, the phenomenon that cold water flows into a sprinkler or a nozzle from the water outlet directly and flows out is avoided, use is more convenient, and a user experience is improved.