Abstract: A water recirculation system for a shower unit comprises a plurality of reservoirs and switching means for selecting from which of the reservoirs the shower unit receives water. A pump recirculates water from a waste trap of the shower unit to the active reservoir. Each reservoir contains a heater. At the user's command, a system of valves is reconfigured so that the shower unit becomes supplied with fresh water circulated from a second reservoir. Meanwhile, the first reservoir is emptied, refilled and reheated to be ready for further use if required. Further pipes may be provided to allow preheating and circulation of the water in the system prior to use of the shower unit; and to allow the system to be flushed with water from a mains supply.