A heating and hot water supply system, including: a combustion unit combusting a fuel to generate a combustion gas; a heat exchange unit heating a heat medium and hot water according to heat exchange with the combustion gas; an exhaust unit that exhausting the combustion gas after heat exchange. The heat exchange unit includes a plate type heat exchanger by laminating vertically-upright rectangular plates with gaps, and is configured to heat the heat medium by causing the combustion gas and the heat medium to alternately flow through the gaps. An inlet for the heat medium is provided at lower corner of the plate type heat exchanger, a discharge opening for the heat medium is provided at upper corner farthest from the inlet, and a hot water passage through which hot water flows in the plate type heat exchanger is provided at upper corner above the inlet.

A heating and hot water supply system, including: a combustion unit combusting a fuel to generate a combustion gas; a heat exchange unit heating a heat medium and hot water according to heat exchange with the combustion gas; an exhaust unit that exhausting the combustion gas after heat exchange. The heat exchange unit includes a plate type heat exchanger by laminating vertically-upright rectangular plates with gaps, and is configured to heat the heat medium by causing the combustion gas and the heat medium to alternately flow through the gaps. An inlet for the heat medium is provided at lower corner of the plate type heat exchanger, a discharge opening for the heat medium is provided at upper corner farthest from the inlet, and a hot water passage through which hot water flows in the plate type heat exchanger is provided at upper corner above the inlet.

The invention is a double-circuit electric boiler for boiling a warming heat-carrying agent and a residential hot water. A hot water supply circuit first container and a second container with an electric heater for the heat-carrying agent of a warming circuit are arranged in a housing. Outer surfaces of inner walls of the warming circuit second container are in a contact with the water of the hot water supply circuit inside the first container. The electric heater for the heat-carrying agent is isolated by the second container walls from a contact with the water of the hot water supply circuit inside the first container. Both containers have separate inlet and outlet ducts and separate isolated temperature sensors. In a second embodiment of the boiler, an electric heater having heating areas isolated by the inner walls of the second container is further mounted in the first container.

A multi-temperature output fluid heating system including an input for receiving a fluid supply, a single heating source, a first output, a second output and a bypass path. The first output is fluidly connected to the input, where the first output is adapted for control by a first control device and to receive heat from the single heating source to achieve a first temperature at the first output. The bypass path fluidly connects the input and the second output. The input is adapted to empty a first portion of the fluid supply into the first output and a second portion of the input into the bypass path. The second output is adapted to receive an output from the first output and an output from the bypass path to achieve a second temperature.

A multi-temperature output fluid heating system including an input for receiving a fluid supply, a single heating source, a first output, a second output and a bypass path. The first output is fluidly connected to the input, where the first output is adapted for control by a first control device and to receive heat from the single heating source to achieve a first temperature at the first output. The bypass path fluidly connects the input and the second output. The input is adapted to empty a first portion of the fluid supply into the first output and a second portion of the input into the bypass path. The second output is adapted to receive an output from the first output and an output from the bypass path to achieve a second temperature.

The present disclosure relates to systems and methods for connecting to an auxiliary power source and operating a water heater. One exemplary aspect is directed to a water heater configured to heat a volume of water. The water heater can include a first heating system configured to operate at a first power and a second heating system configured to operate at a second power. The second power can be less than the first power. The water heater can further include a first AC connection configured to receive externally supplied AC power at a first voltage and a second AC connection configured to receive externally supplied AC power at a second voltage. The second voltage can be less than the first voltage. The water heater can use only the second heating system when the second AC connection receives the externally supplied AC power at the second voltage.

A heat exchanger including a gas inlet through which a combustion gas flows in and a gas outlet through which the combustion gas flows out is provided. The heat exchanger includes a housing in which the gas outlet is formed, a partition member, and a plurality of heat transfer tubes accommodated in the housing. The partition member is mounted in the housing so that there is a portion in which a flow area of the combustion gas is smaller than that of the gas inlet between the gas inlet and the gas outlet.

A processor for a controller of a water heater is configured to receive water heater control parameters and an output from a sensor indicating a measured temperature of water in the water heater. The processor is also configured to determine whether to enter an anti-stacking control mode or to enter a demand anticipation control mode. In the anti-stacking control mode the processor is configured to initiate a call for heat when the measured temperature reaches a trigger temperature, calculate a burner on delay value and set a second timer with the calculated value, and calculate a reduced activation time. In the demand anticipation control mode the processor is configured to increase the variable offset based on a frequency of the demand anticipation control mode being activated, initiate a call for heat, and control, based on the reduced activation time or the increased offset value, the burner.

A heat exchanger including a gas inlet through which a combustion gas flows in and a gas outlet through which the combustion gas flows out is provided. The heat exchanger includes a housing in which the gas outlet is formed, a partition member, and a plurality of heat transfer tubes accommodated in the housing. The partition member is mounted in the housing so that there is a portion in which a flow area of the combustion gas is smaller than that of the gas inlet between the gas inlet and the gas outlet.

A heating and hot water supplying device includes: a circulation passage that connects a heat exchanger and an external heating terminal; a bypass passage that bypasses the heating terminal by branching from the circulation passage; a hot water supply passage for supplying the hot water heated to a preset hot water supply temperature by the heat exchanger for hot water supply; a control unit that controls operations in which this plurality of units are used; and an operation terminal for performing various operations. A distribution valve is provided in the branching portion of the bypass passage. The distribution valve adjusts the distribution ratio so that each of a heating operation, a hot water supplying operation, and a simultaneous heating and hot water supplying operation is possible. The operation terminal is provided with a prohibit switch to prohibit the simultaneous heating and hot water supplying operation.