Abstract: A water heater including a heat pump assembly, a heating element and a controller is disclosed. The controller is configured to activate a quick start mode of the water heater responsive to obtaining a user request and activate the heat pump assembly and the first heating element simultaneously responsive to activating the quick start mode. The controller may obtain an operational parameter associated with a water heater component responsive to activating the heat pump assembly and the first heating element and output a notification indicating the operational parameter.

Abstract: A metering valve for a water heater system is provided. The metering valve is configured to selectively control the amount of water flowing into the water tank and/or cold-water bypass shunt through rotation of a rotor. The rotor is attached to the motor such that when the motor is driven, the rotor is rotated in either the clockwise or counterclockwise direction. The rotor is shaped such that, depending on the degree of rotation of the rotor, the size of the openings at the cold water inlet and the cold water bypass shunt (as well as the water inlet into the metering valve) are adjusted.