A method of operating a water heater, the method including determining a predicted variation of a hot water consumption rate variable over a future time period and calculating a total required operating time of the water heater over that time period. The method further includes determining multiple possible operating profiles of the water heater that provide the total required operating time, and calculating a minimum hot water reserve for each profile. One of the profiles is selected based at least partially on that profile providing a minimum hot water reserve that is not less than a predetermined desired reserve capacity and the water heater is operated over the time period using that profile. The selected profile may be the profile that is calculated to have the lowest operational cost.

A method of operating a water heater, the method including determining a predicted variation of a hot water consumption rate variable over a future time period and calculating a total required operating time of the water heater over that time period. The method further includes determining multiple possible operating profiles of the water heater that provide the total required operating time, and calculating a minimum hot water reserve for each profile. One of the profiles is selected based at least partially on that profile providing a minimum hot water reserve that is not less than a predetermined desired reserve capacity and the water heater is operated over the time period using that profile. The selected profile may be the profile that is calculated to have the lowest operational cost.

A computer-implemented method monitors and/or controls domestic hot water production and/or distribution. The method includes detecting at least two real temperatures of a fluid stored in a heat storage tank at two different positions along a height of the heat storage tank at least at points in time, and acquiring a temperature distribution pattern of heat stored in the heat storage tank and/or corresponding heat distribution pattern data by applying a temperature-distribution-pattern-algorithm to the detected real temperatures detected at the points in time. The fluid is sanitary hot water, and the heat storage tank is a pressurized tank. A computer may carry out the method. The computer may be part of a system. A computer program may include instructions to cause the controller of to execute the method. The computer program may be stored on a computer-readable medium.

A computer-implemented method monitors and/or controls domestic hot water production and/or distribution. The method includes detecting at least two real temperatures of a fluid stored in a heat storage tank at two different positions along a height of the heat storage tank at least at points in time, and acquiring a temperature distribution pattern of heat stored in the heat storage tank and/or corresponding heat distribution pattern data by applying a temperature-distribution-pattern-algorithm to the detected real temperatures detected at the points in time. The fluid is sanitary hot water, and the heat storage tank is a pressurized tank. A computer may carry out the method. The computer may be part of a system. A computer program may include instructions to cause the controller of to execute the method. The computer program may be stored on a computer-readable medium.

A water heating system includes a tank that retains water, a heat pump that heats the water in the tank, and a water heater that heats supplied water by combustion heat of fuel gas. In the water heating system, a tank use mode in which the water in the tank is mixed with tap water and supplied to a plurality of using locations including a bathtub, and a hot water supply use mode in which water supplied from the tank or tap water is heated by the water heater and then supplied to the plurality of using locations are executable. The tank use mode is executable at least in a predetermined second time slot, and a capacity of the tank is set to be equal to or more than a first reference capacity and equal to or less than a second reference capacity.

A water heating system includes a tank that retains water, a heat pump that heats the water in the tank, and a water heater that heats supplied water by combustion heat of fuel gas. In the water heating system, a tank use mode in which the water in the tank is mixed with tap water and supplied to a plurality of using locations including a bathtub, and a hot water supply use mode in which water supplied from the tank or tap water is heated by the water heater and then supplied to the plurality of using locations are executable. The tank use mode is executable at least in a predetermined second time slot, and a capacity of the tank is set to be equal to or more than a first reference capacity and equal to or less than a second reference capacity.

A thermal system for the storage and release of heat is comprised of an electric heater in fluidic communication with a recirculation pump, a heat exchanger for transferring heat to a target space, and a plurality of control valves. The heater may act as its own reservoir, or a separate reservoir may be provided. Fluid within the reservoir is slowly heated at relatively low power levels and is then released quickly on demand just prior to occupying the target space.

A thermal system for the storage and release of heat is comprised of an electric heater in fluidic communication with a recirculation pump, a heat exchanger for transferring heat to a target space, and a plurality of control valves. The heater may act as its own reservoir, or a separate reservoir may be provided. Fluid within the reservoir is slowly heated at relatively low power levels and is then released quickly on demand just prior to occupying the target space.

Method to operate a hot water storage device (10) comprising a tank (11), a heating unit (15), at least one temperature sensor (19, 20), and a controller (21) to control the heating unit (15). The method comprises the following steps: Determine from a water temperature measurement signal provided by the at least one temperature sensor (19, 20) a water usage profile, said water usage profile providing for defined time intervals of a day and/or for defined days of a week a nominal temperature and a nominal volume of the heated water to be stored within the tank. Operate the heating unit (15) in such a manner that for each defined time interval of a day and/or for each defined day of a week the actual temperature and the actual volume of the heated water stored withing the tank corresponds automatically to the respective nominal value of the water usage profile.

Method to operate a hot water storage device (10) comprising a tank (11), a heating unit (15), at least one temperature sensor (19, 20), and a controller (21) to control the heating unit (15). The method comprises the following steps: Determine from a water temperature measurement signal provided by the at least one temperature sensor (19, 20) a water usage profile, said water usage profile providing for defined time intervals of a day and/or for defined days of a week a nominal temperature and a nominal volume of the heated water to be stored within the tank. Operate the heating unit (15) in such a manner that for each defined time interval of a day and/or for each defined day of a week the actual temperature and the actual volume of the heated water stored withing the tank corresponds automatically to the respective nominal value of the water usage profile.