A water heating system can include a first tank-based water heater having a first inlet line and a first outlet line, where the first inlet line provides unheated water to the first tank, and where the first outlet line draws heated water from the first tank. The system can also include a first tankless water heater having a second outlet line, where the second outlet line of the first tankless water heater provides the heated water to a first heated water demand. The system can also include a first valve that controls an amount of the unheated water flowing through the first inlet line to the first tank-based water heater. The system can further include a controller operatively coupled to the first valve, where the controller controls a position of the first valve based on the first heated water demand and a first capacity of the first tankless water heater.

A heat pump for a pool or spa may include a human-machine interface (HMI). The HMI of the heat pump may be movable relative to a housing or body of the heat pump such that regardless of the location and orientation of the installation of the body of the heat pump, the HMI may be positioned so that it is accessible to a user. A heat pump may additionally or alternatively include means for managing condensate created by operation of said heat pump.

A method of controlling a gas powered water heater includes attempting to pick a main gas valve of the main burner using a first pick method. The first pick method includes closing a switch of a valve pick system to couple a capacitor of the valve pick system to the main gas valve for a first length of time to discharge energy stored in the capacitor to the main gas valve, and opening the switch of the valve pick system after the energy stored in the capacitor is discharged to the main gas valve. The controller determines if the main gas valve is open after using the first pick method. When the controller determines the main gas valve is not open, the controller attempts to pick the main gas valve using a second pick method different than the first pick method.

A hybrid tank and tankless hot water system with an inlet bypass and an outlet bypass are configurable between a hybrid heater configuration and an on-demand configuration. In the hybrid heater configuration, the inlet bypass supplies cold water to a cold water inlet of a storage tank and the outlet bypass supplies hot water from an outlet manifold to a recirculation inlet of the storage tank. In an on-demand configuration, the inlet bypass supplies cold water to a cold water manifold for directly providing cold water to hot water heaters and the outlet bypass supplies hot water from the outlet manifold directly to a system hot water outlet. In the bypass configuration, a storage tank and/or recirculation pump are fluidically isolated from one or more hot water heaters to facilitate their maintenance, repair, replacement while still supplying hot water on demand from the hot water heaters.

A hybrid tank and tankless hot water system with an inlet bypass and an outlet bypass are configurable between a hybrid heater configuration and an on-demand configuration. In the hybrid heater configuration, the inlet bypass supplies cold water to a cold water inlet of a storage tank and the outlet bypass supplies hot water from an outlet manifold to a recirculation inlet of the storage tank. In an on-demand configuration, the inlet bypass supplies cold water to a cold water manifold for directly providing cold water to hot water heaters and the outlet bypass supplies hot water from the outlet manifold directly to a system hot water outlet. In the bypass configuration, a storage tank and/or recirculation pump are fluidically isolated from one or more hot water heaters to facilitate their maintenance, repair, replacement while still supplying hot water on demand from the hot water heaters.

A water heater includes a first heater, a second heater, and a controller. The controller can enable different operational modes of the water heater, wherein only the first heater operates, only the second heater operates, or both the first and the second heaters operate. The controller can also be configured to enable a hybrid operational mode and a bypass operational mode. Further, in the different operational modes, the controller can direct water flow to at least one of a first conduit coupled to the first heater, a second conduit coupled to the second heater, and a bypass conduit. The controller can be configured to receive input signals relating to environmental conditions around the water heater and/or an aquatic system in which the water heater is installed.

A smart electric heating device comprises a storage unit, a first heating unit, a second heating unit, a control unit and a first temperature sensing unit. With the first temperature sensing unit to obtain an ambient temperature, the control unit compares the ambient temperature with a maximum increased temperature and a set temperature for controlling the first heating unit and the second heating unit to actuate. In this way, each user can use hot water of sufficient temperature better.

The saving of water in a shower start up is accomplished by a secondary water tank that delivers hot water while water in the pipes is diverted, mixed or separately heated.

Various implementations include a hot water heating system having a spine and two or more water heating units. The spine includes a top surface defining one or more top openings, two or more coupling areas, and cold water, hot water, and fuel manifolds. One or more top openings provide access to a cold water manifold inlet, a hot water manifold outlet, and a fuel manifold inlet. At least one of the coupling areas is located above another coupling area when the spine is oriented with the top surface facing upwardly. The water heating units are coupled to coupling areas such that a cold water inlet of the unit is fluidically coupled to the cold water manifold outlet, a hot water outlet of the unit is fluidically coupled to the hot water manifold inlet, and a fuel inlet of the unit is fluidically coupled to the fuel manifold outlet.

A water heating system having a tank and one or more heat sources for heating water is provided. The water heating system includes a water outlet for allowing egress of water from the tank and a dip tube for allowing ingress of water into the tank. The dip tube includes a first end for coupling with a water source and a second end disposed proximate a base of the tank for discharging water into the tank through an array of holes. Each of the holes is defined in a side wall of the dip tube and laterally discharges water with respect to a longitudinal axis of the second end of the dip tube.