Systems and methods for controlling the output water temperature of a water heater are disclosed herein. The water heater preferably has a water inlet, heating unit, and water output. The system comprises a proportional flow restrictor placed near the water output and a controller which is configured to direct the heating unit to heat the water and the proportional flow restrictor to produce a flow rate of the output water. Temperature sensors may be used to control the proportional flow restrictor. The proportional flow restrictor can also be controlled based on the amount of heat energy applied to the heating unit.

A fluid circulation type heating apparatus includes: a circulation line; a heat radiation member installed on the circulation line; a boiler configured to heat and expand a fluid; a storage tank configured to store the fluid and to supply the fluid to the boiler; a controller configured to control the boiler; and a housing configured to accommodate the boiler and the controller. The apparatus further includes: a backflow prevention means removably installed in the housing and configured to, when mounted to the housing, communicate with the circulation line disposed between the boiler and the storage tank, the backflow prevention means configured to allow the fluid to flow in one direction through the circulation line.

A heat exchanger having a drainage member (1) mounted on an open end (322) of a heat-transfer tube (32), wherein the drainage member (1) contains a flow guide portion (11) including an insertion portion (11a) configured to be inserted into the heat-transfer tube (32) from the open end (322), and a projecting portion (11b) projecting toward an outside of the heat-transfer tube (32) from the open end (322) and extending downward.

A heat transfer tube of a heat exchanger is provided with a first and a second annular convex portions of which outer diameters are partially expanded. The first annular convex portion is positioned on an inner face side of a side plate portion of a case of the heat exchanger and is engaged with a circumferential edge portion of a first hole portion provided for the side plate portion, or the first annular convex portion contacts under pressure with an inner circumferential face of the first hole portion. The second annular convex portion is positioned on an outer face side of a header constituting member and is engaged with a circumferential edge portion of a second hole portion. Thus the side plate portion, the heat transfer tube, and a header are relatively fixed by a simple means.

A boiler loop system including a primary-secondary piping loop interface apparatus including a flow diversion device, and a drain valve, and a drain port in branches from a circumferential sidewall. In an embodiment, supply branch piping and return branch piping connect the primary-secondary piping loop interface apparatus to a boiler and provide attachment points for auxiliary plumbing equipment. In an embodiment, the boiler loop is integrated into the primary loop.

The invention relates to a valve (16) for installation on a water heater comprising a tank (19) with one single welded socket (17), and where cold-water by discharge is led into a connection for a supply pipe (1), through a check valve (4) and down through a cold-water pipe (5a) to the bottom of the tank (19). The hot water in the top of the tank (19) is forced out through a cavity (7) and out of the valve through a connection for a hot water delivery pipe (9). The valve (16) has a connection for a suction pipe (10) for connection to a circulation pump (24) sucking cold water from the bottom of the tank (19) to external heating, wherein the circulation pump (24) leads the consumption water of the tank (19) back to the valve (16) through a connection for a return pipe (11) and to the middle of the tank (19). The return pipe (11) is arranged to be used for return from the circulation pipe between the tank (19) and a hot water cabinet (28).

A water heater includes a hollow body having an inlet and an outlet, a heating element arranged within the hollow body, a cavity formed between a heating surface of the heating element and an interior surface of the hollow body, an outlet tube, and an adapter sleeve. The outlet tube extends externally from the outlet of the hollow body towards the inlet of the hollow body for depositing heated fluid within the fluid tank, wherein the outlet tube is in fluid communication with the inlet of the hollow body. The adapter sleeve arranged at a lower end of the hollow body, wherein the inlet of the hollow body is arranged in the adapter sleeve.

The present invention relates to a hot water supply tank. A hot water supply tank, according to an embodiment of the present invention, comprises: a storage part which accommodates a fluid therein; an internal water outlet pipe through which a fluid flows from the storage part toward a heat pump; an internal water supply pipe through which the fluid flows from the heat pump toward the storage part; and an internal pipe which is disposed inside the storage part, wherein the internal pipe includes: a connection pipe which is connected to the internal water supply pipe, and at least a part of which is flexible; and a discharge pipe which has one end connected to the connection pipe and extending long, wherein a pipe through hole passing through the discharge pipe may be formed at the other end of the discharge pipe. Various other embodiments are possible.

A water heating system can include a first tank-based water heater having a first inlet line and a first outlet line, where the first inlet line provides unheated water to the first tank, and where the first outlet line draws heated water from the first tank. The system can also include a first tankless water heater having a second outlet line, where the second outlet line of the first tankless water heater provides the heated water to a first heated water demand. The system can also include a first valve that controls an amount of the unheated water flowing through the first inlet line to the first tank-based water heater. The system can further include a controller operatively coupled to the first valve, where the controller controls a position of the first valve based on the first heated water demand and a first capacity of the first tankless water heater.

A water heater system includes a water heater rack system with a plurality of vertically stacked tankless water heaters and a water heater storage tank and provides the ability to install a water heater in environments where horizontally oriented heater rack systems would not fit. The tankless water heaters comprise a bifurcated vent arrangement with separate intake and exhaust vents. Accordingly, vent pipes of diameters of two (2) inches or less may be used in comparison to coaxial vent arrangements which may have diameters of three inches or more. The smaller vent pipe diameter allows a plurality of water heaters to be stacked, one above the other, such that the water heater rack system has a maximum height of 76 inches or less. This vertical orientation may allow tankless water heaters to be installed in an environment where a horizontally configured plurality of tankless water heaters would not fit.