Abstract: A hot water re-circulating system (10) in a building (12) comprising a water pump (36) connected between an auxiliary water return line (28) extending from a hot water faucet (22) to a remote hot water heater (14). The water pump (36) is controlled by a timer/switch (42) located at the hot water faucet (22), so that when the hot water faucet (22) is opened, hot water will come out therefrom. In a second embodiment, two water pumps (82) and (92) are each connected between two auxiliary water return lines (68) and (70) extending from two hot water faucets (58) and (62) to a remote hot water heater (50). Each water pump (82) and (92) is controlled by a timer/switch (88) and (98) located at the hot water faucets (58) and (62), so that when the hot water faucets (58) and (62) are opened, hot water wall come out therefrom.