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.

A magnetic filter 10 includes first and second separation chambers 10, 12. The separation chambers 10, 12 each have an inlet and an outlet, and the separation chambers 10, 12 are joined together such that the inlets of the first and second chambers are adjacent, and the outlets of the first and second chambers are adjacent. An inlet port arrangement 28 connects both inlets to a single inlet pipe, and an outlet port arrangement 30 connects both outlets to a single outlet pipe.

A pressure compensation and mixing device for a fluid heater has a mixing unit and a pressure compensation unit. The mixing unit is configured to mix a fluid guided in the mixing unit. The pressure compensation unit is configured to homogenize the pressure in the fluid. The mixing unit and the pressure compensation unit are integrated in a housing which allows for a compact structure. By the mixing unit, a specific homogenization of the temperature of the water heated by the fluid heater is achieved.

A semi-open high-temperature heat pump system including a compressor, a direct-contact condenser, a heat exchanger, an evaporator, a water purifier, a cold water pump, a hot water pump, a circulating water pump, and a vacuum pump. A discharge port of the compressor is connected to the direct-contact condenser, the direct-contact condenser is connected to the evaporator via the heat exchanger, and the evaporator is connected to a gas suction port of the compressor via a gas vent on its top. An outlet of the water purifier is separately connected to the compressor, the direct-contact condenser, and the evaporator via the cold water pump. An outlet at the bottom of the evaporator is connected to the direct-contact condenser via the circulating water pump. The vacuum pump is connected above the direct-contact condenser, and the hot water pump is connected below the direct-contact condenser.

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.

A method for identifying an electric water heater having excessive and abnormal electricity consumption for detecting inefficiency or even a malfunction comprising the following steps: The present invention provides a method for automatic detection of inefficient household heater within a group of monitored households, implemented by a server module and a plurality of household client modules, wherein each of said a server module and plurality of household client modules comprising one or more processors, operatively coupled to non-transitory computer readable storage devices, on which are stored modules of instruction code, wherein execution of said instruction code by said one or more processors implements the following actions: acquiring data relating to each monitored household, including at least part of: environmental conditions, power consumption of each water heater, household profile parameters, and household residents' profile parameters; detect events wherein the water heater's power consumption (P) surpasses a predefined threshold (Pth), and henceforth label said detected events as “water heater activation” events; For each house (i) in the training set, and per each consumption day (d), define a binary label L.sub.id. Said label marks the water heater's activity as either ‘Normal’ or ‘Abnormal’ per house i and day d. Initialize all labels as ‘normal training a machine learning algorithm, to create at least one classification model, wherein all monitored households are classified according to said acquired data and parameters; and Using the Activation Events Classification Model after the training stage, to predict the binary label, L.sub.id, or number activation per day that a specific household (i), from beyond the household training set has surpassed a predefined number of water heater activation events (n) within a day.

A semi-open high-temperature heat pump system including a compressor, a direct-contact condenser, a heat exchanger, an evaporator, a water purifier, a cold water pump, a hot water pump, a circulating water pump, and a vacuum pump. A discharge port of the compressor is connected to the direct-contact condenser, the direct-contact condenser is connected to the evaporator via the heat exchanger, and the evaporator is connected to a gas suction port of the compressor via a gas vent on its top. An outlet of the water purifier is separately connected to the compressor, the direct-contact condenser, and the evaporator via the cold water pump. An outlet at the bottom of the evaporator is connected to the direct-contact condenser via the circulating water pump. The vacuum pump is connected above the direct-contact condenser, and the hot water pump is connected below the direct-contact condenser.

A heat transfer fin (1) includes a plurality of heat-transfer-tube insertion holes (10) aligned in a single stage, a downstream cut portion (3) formed so as to be recessed toward an upstream side of a gas flow passage of combustion exhaust gas, a downstream flange (13) formed on a peripheral edge of the downstream cut portion (3) so as to protrude from one surface of the heat transfer fin (1), and a plurality of first protruding pieces (4a) (4b) (4c) formed between the heat-transfer-tube insertion hole (10) and the downstream flange (13) so as to protrude alternately from both surfaces of the heat transfer fin (1).

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.

The purpose of the present invention is to provide a smoke tube boiler which can prevent leakage of mixed gas and exhaust gas through a gap between a mix chamber and an ignition bar assembly. To this end, the smoke tube boiler according to the present invention comprises: a mix chamber having a mixing space, in which a combustion gas and air are mixed, and a flat plate type burner, the mix chamber being disposed on the upper side of a combustion chamber; an ignition bar assembly assembled to pass through one side of the mix chamber and extending across the upper portion of the combustion chamber to the lower side of the flat plate type burner; and a sealing means for preventing the mixed gas in the mixing space and an exhaust gas in the combustion chamber from leaking to the outside through a gap between the mix chamber and the ignition bar assembly.