Disclosed herein are connectors for a tankless water heater. The connectors can comprise a flange, an aperture extending through the flange having a first diameter, one or more slots extending through the flange, a connector portion substantially surrounding the aperture and extending outward from the flange away from the tankless water heater. The aperture can correspond to an air inlet extending into the tankless water heater, and the air inlet can have a second diameter that is larger than the aperture. To keep the flange in place, the one or more slots can correspond to one or more fastening holes in the tankless water heater. The one or more slots can be substantially parallel and on opposite sides of the aperture. The connector can be in a secured state when the one or more slots are fastened to the one or more fastening holes.

An integrated pressure condensing boiler is provided which relates to the technical field of boilers. The integrated pressure condensing boiler includes a pressure-bearing housing, a heat-exchange furnace arranged in the pressure-bearing housing, a combustion chamber communicating with the heat-exchange furnace and cooling tube groups fixed in the heat-exchange furnace. Heat-exchange medium flows from bottom to top in the pressure-bearing housing and in the cooling tube groups, and exchanges heat with high-temperature flue gas flowing from top to bottom in the heat-exchange furnace, thus achieving a counterflow heat exchanging. The heat-exchange furnace includes a multi-stage heat-exchange chamber with each heat-exchange chamber being cylindrical. The heat-exchange chambers are arranged in sequence from top to bottom to achieve a flue gas diffusing manner that high-temperature flue gas diffuses from center part to periphery and then gathers from periphery to center part.

The present disclosure provides a water heater including a bypass conduit to allow flow of cold water from an inlet pipe to an outlet pipe, and an outlet temperature sensor coupled to the outlet pipe downstream of an outlet of the bypass conduit, to sense temperature of mixture of hot water and cold water in the outlet pipe. An electronic mixing valve is disposed along the inlet pipe to receive temperature data of water mixture from the outlet temperature sensor and compare temperature of the water mixture with a predefined temperature value. In response to determining that the water mixture is flowing through the outlet pipe, the electronic mixing valve regulates the flow of cold water through at least one of the bypass conduit and the inlet pipe until the temperature of the water mixture is within a predetermined range of the predefined temperature value.

Systems and methods are directed to water healer systems, including combi boilers and instantaneous water heaters, for initiating pre-heat and energy savings operations. Embodiments of the present invention can include at least one heat exchanger, a plurality of temperature sensors sensing water temperature at one or more locations within the water heater system, and a control system in communication with the first and second heat exchangers. In embodiments, the control system can be configured to at least: determine an expected demand for hot water, determine a target modulation rate based on the plurality of temperature sensors, and the expected demand, monitor the plurality of temperature sensors and a flow rate, and update the modulation rate based on at least one of a detected change in flow rate and a detected change in at least one of the plurality of temperature sensors.

A water supply system includes a main water tank that is configured to store water and includes a heater to heat the stored water to close to but below a boiling temperature thereof, to provide main heated water. A dispenser water tank receives a portion of the main heated water, and is free of any heating elements to add heat to the water stored therein, and providing dispensable heated water. A water mixer includes a first pipe for receiving the dispensable heated water from the dispenser tank and a second pipe for receiving utility water from a faucet that supplies utility-provided water, with a mixing chamber from which the waters from the first pipe and the second pipe are dispensed and/or in which these waters are admixed.

An improved boiler apparatus having multiple resistive heating elements are provided with fixed resistances that can be rewired to allow dual voltage capability and at the same time, reduced watt density. For 120V operation, the large diameter 9-ohm coil is used alone to provide the lowest possible watt density. For 240V operation, all three heating coils are wired in series, creating a low watt density but high wattage heater.

A hot-water supply system (1) remotely controls, via a server (50) and using a portable terminal device (30), a hot-water supply device (10) connectable to an external communication network (40). The hot-water supply system (1) is provided with a control unit which performs a notification process for notifying at least another, already-associated portable terminal device (30) that the portable terminal device (30) for performing remote control has been newly associated with the hot-water supply device (10). For example, a control unit of the server (50) performs the notification process as the control unit.

A method for controlling an on-demand high volume capable fluid heating system that supplies a total heating power at a turndown ratio and a total flowrate of a fluid supply, the fluid heating system comprising a plurality of heat exchangers fluidly connected in parallel, each of the plurality of heat exchangers comprising: a fluid conductor, wherein each of the plurality of heat exchangers contributes to the total heating power and a portion of the total flowrate of the fluid supply through the fluid conductor; an inlet conductor configured to connect the fluid supply to the plurality of heat exchangers; an outlet conductor configured for receiving the fluid supply downstream of the plurality of heat exchangers; an auxiliary conductor connecting the inlet conductor at a first location and the outlet conductor, the auxiliary conductor comprising a modulating valve; and a pump disposed downstream from the first location on the inlet conductor.

An improved boiler apparatus having multiple resistive heating elements are provided with fixed resistances that can be rewired to allow dual voltage capability and at the same time, reduced watt density. For 120 V operation, the large diameter 9 ohm coil is used alone to provide the lowest possible watt density. For 240 V operation, all three heating coils are wired in series, creating a low watt density but high wattage heater.

A method of assembling a heat exchanger includes the steps of fluidly connecting a plurality of first heat exchanger tubes to a first connecting tube portion at an assembly location to form a first subassembly, fluidly connecting a plurality of second heat exchanger tubes to a second connecting tube portion at the assembly location to form a second subassembly, transporting the first subassembly and the second subassembly from the assembly location to an installation location, and connecting the first subassembly to the second subassembly at a single connection point between the first connecting tube portion and the second tube connecting portion.