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.

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 vent apparatus is used to install a tankless water heater or similar equipment inside an attic without going onto the roof. The vent apparatus may include a main housing and an umbrella assembly movably disposed therein. The main housing (e.g., PVC pipe) is installed through the roof. The umbrella assembly may have a central rod with a flexible umbrella cover on top and an engagement member on bottom. The umbrella assembly is pushed up through the main housing until the engagement member hits the bottom of the main housing and the umbrella cover exits the top of the main housing to cover it and prevent rain from entering the main housing. The bottom of the main housing is then connected to the tankless water heater. Additional embodiments are disclosed for tankless water heaters with an air intake port and a gas exhaust port.

An exhaust adapter includes a cylindrical part for connecting an exhaust pipe of a combustion device to a collective exhaust duct; and a backflow prevention structure for preventing backflow of the exhaust from the collective exhaust duct side to the exhaust pipe side. The backflow prevention structure includes: a damper receiving part formed with an opening through which the exhaust from the exhaust pipe passes; an exhaust damper plate that opens the opening by pressure of the exhaust from the exhaust pipe and closes the opening by its own weight when there is no exhaust from the exhaust pipe; a support shaft that rotatably supports the exhaust damper plate; and a bearing part that supports the support shaft. A pair of shaft hole parts of the exhaust damper plate for inserting the support shaft is formed in a long hole shape.

An exhaust adapter includes a cylindrical part for connecting an exhaust pipe of a combustion device to a collective exhaust duct; and a backflow prevention structure for preventing backflow of the exhaust from the collective exhaust duct side to the exhaust pipe side. The backflow prevention structure includes: a damper receiving part formed with an opening through which the exhaust from the exhaust pipe passes; an exhaust damper plate that opens the opening by pressure of the exhaust from the exhaust pipe and closes the opening by its own weight when there is no exhaust from the exhaust pipe; a support shaft that rotatably supports the exhaust damper plate; and a bearing part that supports the support shaft. A pair of shaft hole parts of the exhaust damper plate for inserting the support shaft is formed in a long hole shape.

A chimney flue heater for selectively inducing an updraft within a chimney flue generally includes a body releasably hanging from a flue liner and a heating assembly to heat air and induce an updraft within the chimney flue. The body includes a hanger assembly having (i) a top member extending outwardly from an upper portion of the planar support and (ii) a side member extending downwardly from the top member and overlapping an outer surface of the flue liner. The planar support extends downwardly from the hanger assembly and along an inner surface of the flue liner. The heating assembly is mounted on the planar support opposite the hanger assembly. A method of using the chimney flue heater is also disclosed.

A chimney flue heater for selectively inducing an updraft within a chimney flue generally includes a body releasably hanging from a flue liner and a heating assembly to heat air and induce an updraft within the chimney flue. The body includes a hanger assembly having (i) a top member extending outwardly from an upper portion of the planar support and (ii) a side member extending downwardly from the top member and overlapping an outer surface of the flue liner. The planar support extends downwardly from the hanger assembly and along an inner surface of the flue liner. The heating assembly is mounted on the planar support opposite the hanger assembly. A method of using the chimney flue heater is also disclosed.

A sealing device comprising: an axially deformable tubular membrane (4) having a first annular end and a second annular end (8), a first annular coupling ring (5; 205) rigidly connected to the first end of the tubular membrane and having a lateral annular wing (10) providing an axial annular attachment space (12) that is axially open on the side of the second annular end of the tubular membrane and is radially located on a lateral side of the tubular membrane, and a second coupling ring (7) rigidly connected to the second end of the tubular membrane and having a projecting lateral annular ring (14) axially extending opposite the first annular end of the tubular membrane and radially offset opposite said axial annular attachment space relative to said lateral side of the tubular membrane. An assembly comprising two coaxial ducts (2, 3) engaged together, between which the sealing device is mounted.

A soundproof fume discharge conduit adapted to be arranged between a ventilation system and an outlet chimney, the conduit defining a fume path therein, wherein at least one side surface of the conduit is provided with at least two protrusions, each protrusion internally defining a respective step-shaped recess, whereby the path is provided with at least two step-shaped recesses adapted to reflect sound waves propagating along the path, and wherein the step shape of each recess is defined by two first walls, which are incident at a first end thereof, and at least one wall of the two first walls is coated with a first sound absorbing material.

A modular exhaust configured for exhausting a flue flow of a heat exchanger, the modular exhaust including a cross tube including an inlet end, an exit end and a central axis, wherein the cross tube configured for receiving the flue flow at the inlet end and channeling the flue flow to the exit end; a condensate drainage exit aperture disposed on a bottom portion of the cross tube, the condensate drainage exit aperture configured for draining condensate from the first heat exchanger; and a vertical tube including a central axis, a top end and a bottom end, the cross tube configured to be connected at the exit end of the cross tube to a portion of the vertical tube disposed between the top end and the bottom end, the central axis of the cross tube is not disposed perpendicularly with respect to the central axis of the vertical tube.