An electric shower water heater unit for connection to a water supply and a mains electricity supply comprises a housing having a shower water outlet to which a shower hose is connectable; an electric water heater housed in the housing and fluidly connectable to a water supply outlet of the water supply and electrically connectable to the mains electricity supply, the electric water heater supplying water to the shower water outlet of the housing; a user-operable controller (20) for controlling a temperature and a flow rate of water supplied to the shower water outlet of the housing, and a control circuit which is housed in the housing and which controls the electric water heater based on inputs received from the user-operable controller (20). The user-operable controller includes a touch-pressure sensitive element (40, 49) for pressing by a user and which is in communication with the control circuit. The control circuit only controls the electric water heater when a pressure imparted by a user pressing the touch-pressure sensitive element (40, 49) is equal to or greater than a predetermined ivalue.