A gas powered water heater includes a storage tank, a main burner, a flame sensor assembly, and a controller communicatively coupled to the flame sensor assembly. The flame sensor assembly includes a probe positioned proximate the main burner to couple an electric current to the main burner through a flame on the main burner and not to couple an electric current to the main burner when the flame is not present on the main burner, and a detector that provides signals representative of the electric current provided through the probe. The controller is programmed to determine a length of time taken for a transition between a signal representative of no electric current and a signal representative of a steady state electric current, and determine, based at least in part on the determined length of time, a strength of the flame on the main burner.

The disclosed technology relates to a solar water heating system including a tank configured to store heat transfer fluid, a solar collector in fluid communication with the tank, and a pump system in fluid communication with the tank and the solar collector. The pump system can include a first pump, a second pump, and a valve assembly. The valve assembly can direct the heat transfer fluid from an outlet of the first pump to the solar collector when the first pump is operating and can direct the heat transfer fluid from an outlet of the second pump to the solar collector when the second pump is operating. The first pump and the second pump can transfer the heat transfer fluid from the solar collector back to the tank when the first pump and the second pump are not operating.

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 heating system configured to be connected to a heating distribution system of a building. The heating system comprises a heat pump arrangement configured to heat a fluid; a stratified heat storage device configured to store the fluid at differentiated temperatures, a mixing arrangement; and a control device for controlling the heating system. The mixing arrangement is configured to subtract fluid from the heat storage device and to regulate the temperature of the fluid entering the heat distribution system and control the temperature of the returning fluid from the heating distribution system. The invention also relates to a method for controlling such a heating system, a computer program, a computer-readable medium, and a control device.

A water heating system can include a water heater having a tank, an inlet line, and an outlet line, where the inlet line provides unheated water to the tank, and where the outlet line draws heated water from the tank. The water heating system can also include multiple sensing devices, where each sensing device of the plurality of sensing devices measures a parameter associated with the tank. The water heating system can further include a controller communicably coupled to the plurality of sensing devices, where the controller determines an amount of heated water in the tank based on measurements made by the plurality of sensing devices.

System and method for grid load-up dual set point. The invention provides a method of operating a water heater having a tank configured to store water. The method includes heating, via a first heating element, a first portion of the water to a first temperature set point. The method also includes heating, via a second heating element, a second portion of the water to a second temperature set point, the second temperature set point being greater than the first temperature set point. The method additionally includes receiving a load-up signal from a grid controller, and heating, via the first heating element, the first portion of the water to the second temperature set point upon receiving he load-up signal.

A method and system of providing hot water efficiently. A cost of heating a volume of water to a predetermined temperature in a first water heater is determined. A cost of transferring a volume of hot water from a second water heater of a network of interconnected water heaters to the first water heater is determined. Upon determining that the cost of transferring the volume of hot water from the second water heater is lower than the cost of heating the volume of water of the first water heater, the second water heater transfers at least part of the volume of hot water to the first water heater. Otherwise, the volume of water is heated to the predetermined temperature in the first water heater.

A method of heating water in a water storage tank. The method includes: selecting an outlet port and an inlet port from at least three ports located in the tank at different heights along a vertical direction. The outlet port is below the inlet port. The method further includes extracting water from the outlet port, supplying the extracted water to an external heat exchanger configured for heating the extracted water, and delivering heated water from the heat exchanger to the selected inlet port.

A system and method for controlling power to a water heater. The method comprises providing the water heater in a locked state, wherein at least one heating element of the water heater is inoperable when the water heater is in the locked state, coupling a digital key module to a communications port of the water heater, and receiving a digital key from the digital key module through the communications port. The method comprises coupling an electrical grid controller to the water heater through the communications port and placing the water heater in an unlocked state, wherein the at least one heating element of the water heater is operable when the water heater is in the unlocked state.

A solar photovoltaic (PV) water heating system includes a tank including at least a first heating unit having at least first and second heating elements, at least one of which is switchable; a PV solar collector; an inverter adapted to convert the output from the PV collector to an alternating power supply; a modulator to modulate the alternating power supply from the inverter; a controller adapted to control the modulator and the switching of the or each switchable heating element; wherein the controller is adapted to control the modulator and the switchable heating elements to maximize the energy drawn from the PV collector.