A water heater including a tank, first and second heating elements, first and second temperature sensors, a communication module, and a controller. The controller is operable to determine a first temperature value related to a first temperature sensed by the first temperature sensor, determine a second temperature value related to a second temperature sensed by the second temperature sensor, and receive a command from the external controller. When the received command is a first command, the controller control current to the first heating element based on the first temperature value traversing a first set point, and controls current to the second heating element based on the second temperature value traversing a second set point. When the received command is a second command, the controller controls current only to the first heating element and not the second heating element, the control being based on the first temperature value.

A heat balancing system for a natural draft gas burning appliance having a flue. When the appliance is in a standby mode, a main burner is shut off and the pilot light remains on. Temperature in the heat exchanger (e.g., temperature of water in a heater tank) may be decreased or increased, respectively, by opening or closing a damper in a flue as needed. If opening the damper does not sufficiently reduce the temperature of the heat exchanger, then the pilot light may be shut off to further reduce the temperature. The pilot light may be turned on again to bring up the temperature. There may be a control or controller to operate the damper to maintain the temperature of the exchanger within a certain range. Electrical power may be provided for the system from a power line, a storage device, or other source.

A water heater system includes a tank defining a fluid chamber and having a top end and a bottom end and a thermal mixing valve. The thermal mixing valve is arranged exterior of the tank and at the top end thereof. The thermal mixing valve includes a first fluid inlet that draws water from the bottom end of the tank, a second fluid inlet that is in fluid communication with the fluid chamber, and a fluid outlet exterior to the tank.

A water heater system includes a tank defining a fluid chamber and having a top end and a bottom end and a thermal mixing valve. The thermal mixing valve is arranged exterior of the tank and at the top end thereof. The thermal mixing valve includes a first fluid inlet that draws water from the bottom end of the tank, a second fluid inlet that is in fluid communication with the fluid chamber, and a fluid outlet exterior to the tank.

A heat balancing system for a natural draft gas burning appliance having a flue. When the appliance is in a standby mode, a main burner is shut off and the pilot light remains on. Temperature in the heat exchanger (e.g., temperature of water in a heater tank) may be decreased or increased, respectively, by opening or closing a damper in a flue as needed. If opening the damper does not sufficiently reduce the temperature of the heat exchanger, then the pilot light may be shut off to further reduce the temperature. The pilot light may be turned on again to bring up the temperature. There may be a control or controller to operate the damper to maintain the temperature of the exchanger within a certain range. Electrical power may be provided for the system from a power line, a storage device, or other source.

A water heater system includes a water tank and a flow-through heating assembly. The water tank contains heated water. The flow-through heating assembly may extend into the water tank and heats water as water is passed through an interior channel of the flow-through heating assembly. In one embodiment, the flow through heater assembly is a thermosiphonic heater having a hollow body and a heating element extending therein such that an annular recess is defined between an interior surface of the hollow body and the external surface of the heating element.

An electric fluid heating system is provided. The system includes first and at least second electrically powered heating elements. A fluid path is associated with each of the first and at least second heating elements and arranged such that heat can be transferred from the heating element to fluid containable within the associated fluid path when said heating element is in an operable condition in use. The first and at least second heating elements are independently operable and/or controllable.

A hot water delivery system includes a water heater, a mixing valve that is coupled to the output of the water heater, and a plurality of loads that are coupled to the output of the mixing valve. A load set point temperature of each load that is representative of a maximum temperature of the hot water that is to be delivered to the respective load is set by a user. Responsive to detecting the occurrence of an event associated with a load of the plurality of loads, a controller of the water heater controls the mixing valve to adjust the temperature of the hot water from the water heater to the load set point temperature associated with the load, provided the load set point temperature of the load is different from a water heater set point temperature at which the water heater maintains the hot water therein.

A hot water delivery system includes a water heater, a mixing valve that is coupled to the output of the water heater, and a plurality of loads that are coupled to the output of the mixing valve. A load set point temperature of each load that is representative of a maximum temperature of the hot water that is to be delivered to the respective load is set by a user. Responsive to detecting the occurrence of an event associated with a load of the plurality of loads, a controller of the water heater controls the mixing valve to adjust the temperature of the hot water from the water heater to the load set point temperature associated with the load, provided the load set point temperature of the load is different from a water heater set point temperature at which the water heater maintains the hot water therein.

A water heater system includes a water tank and a flow-through heating assembly. The water tank contains heated water. The flow-through heating assembly may extend into the water tank and heats water as water is passed through an interior channel of the flow-through heating assembly. In one embodiment, the flow through heater assembly is a thermosiphonic heater having a hollow body and a heating element extending therein such that an annular recess is defined between an interior surface of the hollow body and the external surface of the heating element.