a fun project to solve a screwup :
My current landlord must have been a sadist or a prankster. Who in the right mind places the bath water heater 5 meter away from the bath in the service kitchen ? On top of that the water heater is gas fired and has only one knob to turn the heat up or down with no thermostat. So either you freeze or you boil. Also there is only one water line , so either it comes via the heater or it is direct from the tank. This makes putting a mixing tap impossible
I chose to use two esp8266 modules and a stepper motor to operate the gate valve.