A networked boiler system includes a first boiler, at least one secondary boiler in operative connection with the first boiler and having a plurality of internal sub boilers, a boiler control connected to one of the first or secondary boilers, and an external control connected to one of the first or secondary boilers. The boiler control enables the first boiler to control a boiler parameter of the first boiler, the at least one secondary boiler, and the plurality of internal sub boilers of the at least one secondary boiler.

A heat distribution system, method and computer program product, including an unpressurized tank configured for holding a heat transfer fluid; and one or more submersible heat transfer fluid pumps configured to pump the heat transfer fluid to one or more heat load loops respectively connected to the one or more heat transfer fluid pumps.

Provided are a boiler and a method for stage change control of the boiler. The boiler includes a burner to generate a calorie necessary for producing hot water by burning air and gas, and a controller to perform a stage change control operation, when the number of times, in which the stage is changed, is equal to or greater than a reference number of times, for a predetermined time, based on information on occurrence of the change of the stage in the burner, while hot water is used.

A method of controlling a heating system includes: obtaining, from a power supply source, information specifying an output modulation period during which power consumption by a heat pump unit is to be reduced; and controlling, based on the information obtained in the obtaining, an amount of heat generated by the heat pump unit. In the controlling, the heat pump unit is caused to generate a first amount of heat per unit time in a period other than the output modulation period, and generate a second amount of heat per unit time during the output modulation period, the second amount of heat being less than the first amount of heat.

A regulating method for a heating and/or cooling system uses at least one load circuit (6), through which a fluid as a heat transfer medium flows and switches the at least one load circuit (6) on and off in dependence on a room temperature in a room to be thermally regulated by the at least one load circuit (6). A feed temperature (T.sub.mix) of the fluid fed to the at least one load circuit (6) is set in dependence on the relative switch-on duration (D) of the at least one load circuit (6). A manifold device is also provided for a heating and/or cooling system with a control device for carrying out such a regulating method.

Thermal targeting technology is used to continuously adjust boiler target temperature to the minimum necessary to satisfy the required heating load. Responsive to and initiated by a first call for heat, boiler target temperature is reduced by a predetermined amount upon or subsequent to the call for heat. Once the boiler temperature reaches this new target, a call timer is activated. If demand for heat is satisfied before a time set point is reached, the system ceases providing additional heat energy until the next heat demand. Responsive to and initiated by a next call for heat, the boiler target temperature is again reduced by the predetermined amount upon or subsequent to this next call for heat. Each time the heat demand is satisfied within the predetermined time interval, the boiler target temperature is reduced. If heat demand is not satisfied, a thermal boost is provided at set time intervals until the call for heat is removed.

A method for detecting malfunction of an electric boiler, the method including: a) detecting over scale accumulation by the steps of: metering the boiler's heating cycle, being a time from activating the boiler by a thermostat thereof until deactivating the boiler by the thermostat; if the heating cycle is longer than a threshold, then indicating over accumulation of scale in the boiler; b) detecting a malfunction of insulation of the boiler, by the steps of: metering the boiler's cooling cycle, being a time from deactivating the boiler by a thermostat thereof until reactivating the boiler by the thermostat; if the cooling cycle is shorter than the threshold, then indicating malfunction of insulation of the boiler; thereby allowing indicating malfunction of said boiler only by metering the heating and cooling cycles of said boiler.

A room heater is operated on receiving an on-command from a thermostat when a detected temperature detected by a second room-temperature detector falls below a first reference temperature, and is stopped on receiving an off-command when the temperature detected by the second room-temperature detector is above a second reference temperature that is set higher than the first reference temperature or when the thermostat is manually operated to be switched off. A setting temperature for temperature control to be carried out when the on-command is received again is updated according to a difference between the set temperature and the temperature detected by the first room-temperature detector on receiving the off-command. When the off-command is received before passing a predetermined period of time after receiving the on-command, the updating of the set temperature is prohibited if the temperature detected by the first room-temperature detector is below a predetermined minimum lower reference temperature.

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 hot water supply apparatus of the present invention includes: a direct water inlet pipe into which direct water is introduced; a heat exchanger for heating direct water introduced through the direct water inlet pipe with combustion heat of a burner; a hot water supply pipe for discharging the hot water heated in the heat exchanger; a bypass pipe connected between the direct water inlet pipe and the hot water supply pipe so as to mix a part of the direct water introduced through the direct water inlet pipe with the hot water discharged through the hot water supply pipe; and a pressure reducing valve provided on the bypass pipe and configured to reduce the pressure of water passing through the inside of the bypass pipe to supply the water to the hot water supply pipe when hot water is supplied.