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 pressure compensation and mixing device includes: a mixing unit configured to mix a fluid guided in the mixing unit; and a pressure compensation unit configured to restrict pressure rising in the fluid. The mixing and pressure compensation units are integrated in a container unit. The mixing unit has a mixing volume. The pressure compensation unit has a pressure compensation volume. The mixing and pressure compensation volumes adjoin each other and are separated from each other at least partially by a common separating wall. The pressure compensation unit is arranged inside the mixing unit. The mixing unit includes: an inlet tangentially arranged on the mixing volume such that a fluid let in through the inlet flows in tangentially into the mixing volume; and an outlet axially arranged on the mixing volume such that a fluid let out through the outlet flows out of the mixing volume axially.

An improved boiler apparatus having a removably couplable heating element that can have resistive heating elements are provided with fixed resistances that can be rewired to allow variable wattage usage of the heating element. Some heating element assemblies can include more than one heating coils or heating element. The heating elements can be wired in series, or parallel thereby creating a low watt density but high wattage heater.

A tooling and method for flexible through connection of a double-liner water heater. The tooling includes a transition shaft, a tooling connecting plate and a fastening screw. The method includes: allowing a shaft head of the transition shaft to be in fit with an inner surface of an outer flange of a lower liner for welding; allowing an end hole to be in fit with an outer surface of an inner flange of an upper liner for welding; after welding seams are cooled, removing the tooling, and enameling the upper and liners; forming through-flexible connection between the inner and outer flanges; and firmly fitting the upper and lower liners together with two steel strips to ensure that a gap between the upper and lower liners is not greater than 7 mm.

A system includes a current source circuit; a system power input; and load switching circuitry coupling the current source circuit and the system power input to an output configured to couple to a vaporizer heating element. The current source circuit, the system power input, and the load switching circuitry form part of an integrated circuit. Related apparatus, systems, techniques, and articles are also described.

Provided are a housing assembly and a water heater. The housing assembly includes a bottom plate assembly and an outer housing. The outer housing is provided with a hooking fitting portion, the bottom plate assembly includes: a base and a supporting portion, a crimping space for positioning the outer housing is formed between at least portion of the supporting portion and the base. The hooking fitting portion is hooked with the crimping space.

An offset mounting bracket that comprises a primary member and a stabilization member can be used to mount multiple heat engines to a water storage tank. An offset mounting bracket can include a primary member, having a top surface, a bottom surface, an inner surface, and an outer surface. The offset mounting bracket can also have a stabilization member, having a top surface and a bottom surface, a supporting surface that is opposed and connected to the primary member outer surface. The offset mounting bracket can also have a connecting member. The connecting member can be configured to fasten to the top of a water storage tank. There, the offset mounting bracket, can provide a surface to mount a heat engine that otherwise would not fit onto the water storage tank structure.

An exhaust duct includes an upper duct being open at opposite ends thereof and a lower duct being open at a tip end thereof. One end of the upper duct is connected, inside an enclosure of a water-heating device, to an exhaust adaptor disposed on the enclosure, and an opposite end of the upper duct communicates with the tip end of the lower duct. The upper duct is connected to the lower duct so as to be slidable along a reference direction in which the lower duct extends from the tip end of the lower duct, and the upper duct is configured to be separated from the exhaust adaptor by sliding along the reference direction.

A system includes a current source circuit; a system power input; and load switching circuitry coupling the current source circuit and the system power input to an output configured to couple to a vaporizer heating element. The current source circuit, the system power input, and the load switching circuitry form part of an integrated circuit. Related apparatus, systems, techniques, and articles are also described.

A combustion device includes: a gas proportional valve; a control portion; a driving circuit; and a monitoring circuit. The monitoring circuit includes: a voltage generating portion configured to generate monitoring voltages corresponding to a driving current; and a branch output portion configured to output the monitoring voltages to a plurality of terminals of the control portion. When a voltage difference between the monitoring voltages input to the plurality of terminals is a determination reference value or more, the control portion determines that there is a failure of the monitoring circuit. When the voltage difference between the monitoring voltages is less than the determination reference value, and at least one of the monitoring voltages does not fall within a predetermined normal range while the gas proportional valve is controlled to become a predetermined state, the control portion determines that there is the failure of the monitoring circuit.