A system for heating a first fluid flow from a first temperature to a second temperature, the system including a hot water supply line for receiving the first fluid flow at a first end and exhausting the first fluid flow at a second end; and a heating system including a heat engine, a thermal battery and a heat exchanger, wherein the thermal battery is configured to be replenished at a point of heat transfer by the heat engine and the hot water supply line is configured to receive heat from the thermal battery via the heat exchanger to elevate the temperature of the first fluid flow from the first temperature to the second temperature.

A system and method for controlling a water heater that operates according to a voltage supply includes a temperature sensor, mounted on at least one of a temperature and pressure (T&P) valve of the water heater and a hot water line of the water heater, that generates a temperature signal corresponding to a first temperature of the at least one of the T&P valve and the hot water line. A control module mounted on the water heater includes a switching module that receives the voltage supply and outputs the voltage supply to the water heater. The voltage supply passes at least one of through and adjacent to the control module. The control module determines a second temperature of water within the water heater based on the temperature signal and selectively actuates the switching module to turn on and turn off the voltage supply to the water heater based on the second temperature.

A heating system includes a heat pump that provides heat to a major fluid circuit and a minor fluid circuit for performing different heating operations. The system includes a power source having a variable cost and a controller configured to regulate flow of the major and minor fluid circuits to perform the heating operations. The controller is configured to receive information regarding the variable cost of the power source and distribute flow between the major and minor fluid circuits to perform the heating operations to minimize the electricity cost. The combined enhanced demand regulation and enhanced output regulation amplifies the total heat output and power consumption while permitting greater use of a power source of varying cost (e.g. PV)thereby minimizing overall daily operating cost.

A system for space heating or cooling a heated space includes a heat pump including a refrigeration circuit for transferring heat between a heat source and a heat load for heating and cooling operations. A controller controls the heat pump to perform the heating and cooling operations. A user interface receives user inputs, wherein the user inputs include an indication of discomfort based on temperature. The controller creates a profile for a minimum comfortable temperature level and a maximum comfortable temperature level, and the controller controls the heat pump to perform the heating and cooling operations in accordance with the profiles for the minimum and maximum comfortable temperature levels. The controller may generate an optimized heat demand plan in accordance with predictions of outdoor and indoor temperature, cost, and demand. The plan is optimized to cost-effectively maintain the temperature of the heated space within the comfortable temperature range defined by the profiles.

A system for heating water to improve safety and efficiency. The system may have normal operation measured in time. After a time of normal operation, a water temperature setpoint may be checked. If the setpoint is not at a certain level, normal operation may continue. If the setpoint is within the certain level, water temperature may be measured. If the water temperature is less than a desired level, one or more draws of water may be measured for a preset temperature drop. If the draws do not meet the temperature drop, a return to check the setpoint may be made. If the draws meet the temperature drop, the setpoint may be reduced and a time of normal operation may be measured to determine whether a burn cycle occurs within the time. If not, normal operation may continue; but if so, a return to check the setpoint may be made.

A hot water supply system includes a hot water storage tank configured to store hot water, a plurality of temperature sensors that are installed in the height direction of the water storage tank and that detect temperatures at their installed positions, a main-unit-side hot water supply device that heats hot water in the hot water storage tank, a sub-unit-side hot water supply device, a main-unit-side control board equipped with control means that controls the corresponding hot water supply device, and a sub-unit-side control board. Signals sent from the temperature sensors are input in a distributed manner among the main-unit-side control board and the sub-unit-side control board, and each of the control boards are communicably connected to each other by a transmission line.

A combined air-conditioning and hot water supply system simultaneously executes the cooling operation of a use unit and the hot water supply operation of a hot water supply unit, wherein the combined air-conditioning and hot water supply system operates in a cooling priority mode when the temperature differential T.sub.wm between a set hot water supply temperature T.sub.wset and the inlet water temperature T.sub.wi of a plate water-heat exchanger is smaller than a priority operation determination threshold M that is set in advance, and operates in a hot water supply priority mode when the temperature differential T.sub.wm becomes equal to or higher than the priority operation determination threshold M. This simultaneous execution of cooling and hot water supply operations prevents hot water from running out.

A water heater includes an electrical junction box that receives a voltage supply. The electrical junction box includes at least one cover plate for providing access to an internal portion of the water heater. The voltage supply passes through the at least one cover plate and connects to internal wiring of the water heater. A method for providing a control module on the water heater includes routing service wiring for providing the voltage supply to the water heater into an electrical connection portion of the control module, routing the internal wiring of the water heater into the electrical connection portion of the control module, and connecting the service wiring to the internal wiring of the water heater within the electrical connection portion of the control module.

A hot water supply system that can reduce energy consumption is provided. The hot water supply system includes a liquid heater for heating a liquid, a liquid-water heat exchanger, a water-heating circuit in which the liquid is circulated between the liquid heater and the liquid-water heat exchanger, a lower outward path for leading water from a lower part of a hot water storage tank to the liquid-water heat exchanger, the upper return path for leading the water from the liquid-water heat exchanger to an upper part of the hot water storage tank, a middle outward path for leading the water from a middle part of the hot water storage tank to the liquid-water heat exchanger, a middle return path for leading the water from the liquid-water heat exchanger to a middle part of the hot water storage tank.

A modular heat pump water tank is provided. The modular heat pump water tank comprises a tank unit including a tank for containing heated water; a heat pump unit including a heat pump for providing heat to the tank; and a heat exchanger arranged externally to the tank for transferring heat from the heat pump to water from the tank. The tank unit and the heat pump unit are adapted for mounting to one another to form an integrated heat pump water tank.