Integrated recirculation pump for non-condensing water heater

A hot water bypass system for connection with a tankless water heater, the tankless water heater comprising a cold water inlet and a hot water outlet, a temperature sensor configured to sense a temperature of water flowing in the cold water inlet, the tankless water heater further comprising a controller configured to provide a control signal in response to the temperature sensor detecting a predetermined temperature, the hot water bypass system comprising:

• a hot water supply line configured to be fluidically connected to the hot water outlet of the tankless water heater;
• a water pump comprising a water pump inlet and a water pump outlet, wherein the water pump outlet is configured to be fluidically coupled to the cold water inlet of the tankless water heater, wherein the water pump is configured to stop in response to receiving the control signal;
• a cold water supply line fluidically coupled to the water pump inlet and comprising a cold water supply port;
• and
• a bypass circuit fluidically coupled between the cold water supply line and the hot water supply line between, the bypass circuit comprising a water flow control unit, wherein the water flow control unit is configured to permit a flow of water from the hot water supply line to the circulating water through a hot water supply line for receiving water from an outlet of the tankless water heater;
• circulating water from the hot water supply line through a bypass circuit to the cold water supply line, wherein the bypass circuit comprises a water flow control unit configured to permit a flow of water from the hot water supply line to the cold water supply line when a pressure drop across the bypass circuit is greater than a second pressure drop across the hot water supply line;
• receiving by the water pump, responsive to circulating water through the bypass circuit, a control signal to stop the water pump;
• and
• stopping pumping water by the water pump in response to receiving the control signal.