Abstract: Disclosed is a heat exchanger that has an internal air flow pattern such as a helical pattern. The heat exchanger includes a shell that encompasses an inner series of heat exchange tubes and an outer series of heat exchange tubes. A baffle sheet is juxtaposed next to the outer series of heat exchange tubes. And the baffle sheet is configured to direct air flow within the heat exchanger in a configuration, such as a helical configuration, from a center of the shell toward an outer region of the shell.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one heat sensitive entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: A water heater includes a water container, a combustion chamber adjacent said water container having at least one inlet to admit air and extraneous fume species into the combustion chamber, at least one inlet comprising a metal plate having a thickness of about 0.4 to 0.6 millimeters and through which pass a plurality of ports, each port having a quenching distance not greater than about 0.6 mm, and being capable of confining ignition and combustion of the extraneous fume species within the combustion chamber; and a burner associated with the combustion chamber and arranged to combust fuel to heat water in the container.

Abstract: An air flow control and routing apparatus for attaching to a water heater, to restrict entry of floor-level gases into the water heater, includes a substantially annular skirt for surrounding a base portion of a water heater. Preferably, the skirt has a closable pilot access door formed therein. The apparatus also includes at least one air intake tube attached to the annular skirt for transporting inlet air therethrough, the air intake tube having an elevated inlet, relative to the skirt, when the apparatus is in an installed orientation thereof. In this first embodiment of the invention, the apparatus is constructed and arranged to feed indoor air, from a portion of a room above floor level, to a water heater combustion chamber, located at the lower end of a water heater, when installed thereon. The invention also encompasses a water heater having the air flow control and routing apparatus installed thereon, and a method of routing inlet air into a water heater using the described apparatus.

Abstract: A water heater of the invention includes a water container; a combustion chamber adjacent the water container; a burner associated with the combustion chamber; a flue connected to the combustion chamber; a blower assembly positioned to receive combustion products from the flue and convey the combustion products to a remote location; and a pressure switch positioned to detect blockage of combustion products away from the blower assembly and flow of air from the flue prior to initiation of combustion in the combustion chamber.

Abstract: A fluid heating and pumping apparatus for use with hot fluid space heating systems includes a fluid tank containing heated fluid and a collapsible bladder contained within the fluid tank for absorbing expansion of the fluid within the fluid tank as it is heated. An air venting device is mounted at a high point in the fluid tank to discharge any air as the heating system is filled with fluid and operated. A fluid circulating impeller, volute, and pressure bypass valve apparatus are also contained within the fluid tank and are connected to an outlet in the fluid tank through which heated fluid is pumped to heat transfer components of a space heating system. A fluid mixing apparatus is attached to the fluid circulating impeller to mix heated fluid from the fluid tank with cooled fluid returned from the heat transfer components to thereby provide fluid having a desired temperature.

Abstract: A combustion burner includes a housing secured to the top of a water heater, a gas tube in fluid communication with a source of gas and depending vertically from the housing and positioned within a heat exchange tube of the water heater. The An ignition assembly depends vertically from the top of the housing through the gas tube and into the heat exchange tube. An angled nozzle, extending from the housing, transports air from an air blower through the housing and into an annulus defined between the exterior of the annular chamber and the interior of the heat exchange tube. A deflector plate having a first and second series of slots and adjacent louvers effects the mixture of the gas and air in the interior of the heat exchange tube and enables the production of a long narrow flame within the heat exchange tube.

Abstract: An apparatus (10) for transferring heat to a fluid from combustion gases including a housing (12) extending between a first end (14) and a second end (16). The apparatus further includes a burner (24) in which a combustible gas and oxygen react to form hot combustion gases which flow from the burner to a gas outlet (28) in the second end. The fluid flows in a length of helically coiled tubing (30) extending the length of the housing. The tubing includes a fin portion (36) which is spirally wound about the length of tubing. The apparatus further includes a core member (40) which extends within the coils of the tubing, and which engages the tubing. The core member includes a spirally-wound threaded area (62) about which the tubing is wrapped. The core member further includes a recessed portion (66) which creates stagnant air pocket adjacent the end of the core member.

Abstract: A water heater including a water container; a combustion chamber located adjacent the container, the combustion chamber having a floor portion with an opening; a conduit extending upwardly from and being substantially sealed to the opening; a burner located inside the combustion chamber; and a flame trap positioned across the conduit, the flame trap permitting ingress of air and/or extraneous gases into the combustion chamber and prevent egress of flames from the structure.

Abstract: A foam distribution jacket (10) for containing an insulating expandable liquid foam mixture (44) prior to expansion into a space (17) between a hot water tank (22) and an outer casing (29) secured thereabout. The jacket (10) comprises a pair of sheets (11-12) which are superimposed to define a bottom trough section (13) having a straight bottom edge (15) and opposed end edges (16). A seal (17) is formed along the straight bottom edge and the opposed end edges to form the trough (13) and to interconnect the sheets (11-12). The pair of sheets (11-12) converge to a crest portion (19) at a top end section (14) thereof. An attachment hole (20) is provided in the crest of an inner one of the pair of sheets (11-12) and is adapted to attach the jacket (10) in a depending manner from a nipple (21) in a top wall (48) of a hot water tank (22). The method of insulating a surrounding space (27) formed between the hot water tank (22) and the outer casing (29) using the foam distribution jacket (10) is also described.

Abstract: A tank structure of a hot-water supply unit capable of permitting tap water under a high pressure to be supplied thereto without using any safety mechanism. An inner barrel of a tank body is formed by rounding or bending a flat plate of an increased thickness by rolling and then joining both lateral ends of the plate to each other by welding. The inner barrel and an outer barrel are joined together through a joint ring of a thickness between a thickness of the inner barrel and that of the outer barrel. Thus, the tank body can be readily manufactured using any specific equipment.

Abstract: A protective collar means for surrounding the lower periphery of a cylindrical water heater. The collar means comprises a cylinder attached at the top and bottom edges to flanged and grooved rings for keeping the cylinder stable. The collar means may be easily assembled by placing the cylinder inside the flange of the lower ring and placing the flange of the upper ring on top of the cylinder. The collar means is preferably secured by a plurality of springs, which attach to the upper and lower rings to keep the collar means assembled. The collar means is spaced away from the walls of the water heater so as to ensure adequate ventilation of the air space surrounding the water heater, but is close enough to contain any fires or explosions that may occur near the gas flames.

Abstract: An inlet is provided for delivering water into a water heater through a port in its side. The inlet includes a conduit having a distal portion that extends toward a bottom of the water heater. That portion includes means for deflecting the water flow in order to reduce the generation of temperature gradients that otherwise tend to develop within water heater tanks. A water heater assembly including such an inlet is also described.

Abstract: A fuel-fired water heater has a combustion chamber disposed beneath the storage tank portion of the water heater. The bottom side wall of the combustion chamber is defined by an annular perforated wall structure with a perforated mounting plate structure being removably secured to the underside of the wall structure over the central opening therein. A burner and associated pilot/thermocouple assembly are secured to the upper side of the mounting plate and project upwardly into the combustion chamber, with the piping and wiring of the burner and pilot/thermocouple assembly extending externally beneath the combustion chamber, outwardly through a side wall access passage, and then turning upwardly along the outside of the water heater for connection to a thermostatic fuel valve. To remove the bottom plate-mounted burner and pilot/thermocouple assembly the fuel supply piping must first be decoupled from the thermostatic valve, thereby assuring that the access plate cannot be removed while the burner is firing.

Abstract: The invention relates to an apparatus for heating fluids which includes a combustion chamber (20) in which the head (21c) of the burner with the burner openings (39) for the flames is juxtaposed with a wall (21a, 21b) of the chamber itself separating this latter from the lower portion of the apparatus; in the event of flammable substances being present in the environment surrounding the apparatus, these can enter the combustion chamber only through the openings (39) and the similar slots (50) formed in the wall (21a, 21b). This enables the ignition element (25) to ignite these substances as soon as they enter the chamber (20), thus preventing the formation of unwanted explosive or flammable mixtures in the chamber (20) and thereby contributing to the safety of the apparatus.

Abstract: An appliance safety shield for gas-burning appliances to prevent heavier-than-air vapors from contacting a pilot light, the safety shield including a floor structure for mounting the safety shield thereon and a mounting strip mounted on the floor structure in generally fluid-tight connection therewith. The mounting strip extends circumferentially around the gas-burning appliance such that the mounting strip substantially completely surrounds the appliance. A generally flat, semi-rigid shield wall having a lower edge is mounted in the mounting strip in generally fluid-tight connection therewith such that the shield wall extends generally upright, the shield wall extending along the mounting strip such that the shield wall substantially completely surrounds the appliance. The shield wall, the mounting strip and the floor structure cooperate to restrict heavier-than-air vapor access to a gas-burning appliance whereby accidental ignition of flammable vapors is prevented.

Abstract: A removable dam provides a way to prevent liquid insulation from interfering with electrical components and from squirting out an opening in the jacket of a hot water heater.

Abstract: An air inlet system for gas water heaters that prevents or delays the ignition of fumes from flammable liquids accidentally spilled on the floor. The air inlet is above the quickly combustible fumes from spilled liquids, allowing time for personal escape or other response. Two concentric air baffles are placed around the tank of the water heater, and are sealed against the floor. They are spaced from each other and from the tank, forming two concentric air chambers around the tank which are open at the top. The inner air baffle is taller than the outer baffle, and has holes or gaps around its lower end for air passage. When the burner is operating, combustion inlet air enters the top of the outer air chamber, travels downward, passes through the holes in the inner baffle, and under the tank to the burner.

Abstract: A water heater having a vertical tank and a coil pipe located coaxial around the tank with a vertical ring space between them that serves as a ring combustor (bottom portion) and a flue for hot gases (upper portion). Assembly of low pressure (from about 500 Pa) plenum blower with air-blast gas burner is located right beneath of ring combustor. The burner's nozzle enters into the ring combustor tangentialy. A venting tangential outlet is located on top of the ring flue. The tank's water inlet ends with a nozzle having tangential direction. It is another water heater with two coaxial vertical coil pipes with a ring space between them and without a tank for hot water. The means for combusting fuel and venting gases are the same as in the preceding object.

Abstract: A water purifier which purifies water by superheated steam. The water purifier includes a raw water reservoir for contaminated water; a heater at least partially disposed within the raw water reservoir and including a heat source, an inlet for steam and an outlet for superheated steam; an inlet conduit in fluid communication with the inlet of the heater for transporting steam produced by boiling said raw water; and a condenser in fluid communication with the outlet of the heater. The heater both boils the raw water to produce a substantially saturated steam and superheats the substantially saturated steam. The water purifier can further include a purified water reservoir in fluid communication with the condenser.

Abstract: A gas water heater including a water container adapted to be heated by a gas burner; and an enclosure surrounding the burner, the enclosure having at least one entryway adapted to allow air and fumes to enter the enclosure without igniting flammable gases or vapors outside of the enclosure.

Abstract: Apparatus for heating and storing water comprises a tank 10 for holding a quantity of water 15 within a space 11 between studs 12 in a wall or like surface 13 of a room 14. An inlet conduit 16 conveys water into the tank 10, and an outlet conduit 17 conveys water out of it and on to another entity 36. A heater 32, spaced apart from the tank 10, receives water from a supply source at a lower temperature, heats it to a higher temperature, and communicates the heated water to the inlet conduit 16. Reinforcing structural members 25 and locator tabs 22 allow for economic construction and ease of installation. A typical tank 10 comprises a hollow parallelopiped having its front surface member 20 in the plane of the surface 13 of the room 14 and its back surface in a plane behind that of the surface 13.

Abstract: Disclosed herein is a fire safety and prevention method, system and apparatus for preventing flammable fumes or vapors from entering into the pilot light or flame area of a gas hot water or other type of heater and igniting into a fire, which is easily installed at low cost and without special expertise.The preferred embodiment is a simple metallic or similar cylinder placed around the heater, with appropriate vapor-tight seals, which will prevent flammable vapors moving near the floor from entering the heating area and igniting.Also disclosed is a method, system, apparatus and method to incorporate this safety feature into the manufacture of new gas hot water and other heaters.

Abstract: A method for gas supply pressure control is disclosed. Gas is supplied to a gas burner at a gas supply pressure which is higher than an ignition pressure, and after the ignition of the gas burner, the gas supply pressure increases during a predetermined time until fluid to be heated reaches a target temperature. The increase of the gas supply pressure is performed gradually according to a predetermined number of pressure levels set between the ignition pressure and maximum gas supply pressure of the gas boiler. If the fluid reaches the target temperature, the gas is supplied according to a corresponding to the target pressure temperature. Since the time that the gas is supplied at the maximum gas supply pressure is reduced during the time of initial operation of the gas boiler and during the operation of the gas boiler, the noise resulting from combustion is reduced.

Abstract: The present invention is a commercial water heater comprising a tank dimensioned to hold a quantity of water, a blower, a heater, a heat exchanger in the water, and a control system. The heat exchanger includes a central tube running from the top of the tank to the bottom and a coil connected to and encircling the central tube. The heater is mounted inside the central tube, and the blower is mounted to the top of the tank, which together simplify manufacture and servicing. The blower is capable of delivering sufficient air for combustion at a pressure and velocity sufficient to drive the exhaust gases fifty feet beyond the water heater outlet, thus avoiding the need for a chimney. The water heater according to the present invention has an average efficiency of 93% with a 1% standby loss and is considerably cheaper to manufacture than other similarly efficient water heaters.

Abstract: A method and apparatus for masking components of a hot water tank from insulation wherein a carrier sheet containing a pair of inflatable rings is insertable into the space between the inner tank and outer shell of the hot water tank. The inflatable rings surround electrical components on the inner tank to prevent insulation injected into the space from covering the electrical components. Inflatable bags are insertable into threaded bores on fittings connected to the inner tank to prevent the insulation from covering the threaded bores, and to prevent insulation from escaping to the outside of the outer shell.

Abstract: A fuel-fired, forced draft, down-fired water heater is provided with an improved combustion product flow path that permits the heater to operate with improved fuel efficiency, lowered CO and NOx emissions, and an improved water heat input distribution along the vertical length of the heater. The water heater includes a vertically oriented tank with a vent plenum structure formed at the top end of the tank interior and having an outlet passage connectable to an external combustion product vent pipe. A centrally positioned submerged vertical burner tube extends downwardly from the vent plenum and has an open lower end extending into a submerged turn bowl disposed at the bottom end of the tank interior. Extending upwardly from the turn bowl within the tank interior, and symmetrically arranged about the centrally disposed burner tube, are a plurality of vertical flue tubes that communicate the interiors of the turn bowl and the vent plenum.

Abstract: A power vented water heater has a radiant gas burner located in a combustion chamber disposed beneath the storage tank portion of the water heater, and a draft inducer fan supported above the top end of the storage tank by a one piece molded plastic adapter fitting having a tubular body interconnecting the upper end of the water heater flue to the inlet of the fan, and a transverse outlet leg. A combustion gas discharge pipe is connected to the fan outlet, and an air intake pipe has a first portion connected to the outlet leg of the adapter fitting to deliver combustion gas cooling air thereto, and a second portion coupled to the burner inlet to deliver combustion air thereto along with gaseous fuel introduced into the second portion of the air intake pipe from an externally mounted gas valve. Integral orifice structures within the adapter fitting automatically maintain a predetermined ratio among the combustion gas, cooling air and combustion air flows.

Abstract: A hot water heater has an expansion tank below the water tank and aligned with the water tank, so both water tank and expansion tank occupy the same floor space. The expansion tank is connected to the water tank by a pipe, so expansion due to heating of the water is absorbed by the expansion tank. For gas fired heaters, the burner for heating water in the water tank is disposed above the expansion tank and below the water tank, so the burner is above the floor sufficiently to comply with gas safety regulations.

Abstract: Apparatus for improving the efficiency of a water heater having a tank, a burner and a flue, the flue being disposed within the tank for evacuation of burned combustion gases therethrough with resulting heating of water in the tank, generally including combustion gas deflector for enhancing heat transfer from the combustion gases through a flue wall and into surrounding water during ignition of the burner, a vent damper for preventing ambient air in the flue, heated by the directing means and flue, from escaping the flue during nonignition of the burner.

Abstract: A water heater is provided for connection to a heated fluid source for transfer of heat from the heated fluid to water in the water heater. The water heater includes a shell having a water storage tank and a heat exchange chamber mounted within the tank. The water heater also has an inlet tube and outlet tube for the introduction and removal of water from the tank. A supply line is connected to the heat exchange chamber to introduce heated fluid into the chamber. A return line, also connected to the heat exchange chamber, removes fluid for reheating. Water stored in the tank is heated by heat exchange from heated fluid recirculated through the heat exchange chamber.

Abstract: An instantaneous gas water heater comprising a control panel, a heat transfer section, and a blower section. The control panel includes an electronic controller, a gas solenoid valve, and a means to prove the operation of a blower. The heat transfer section comprises an inner jacket enclosing a combustion chamber and an outer jacket enclosing the inner jacket. The combustion chamber contains an ignition means, a combustion means, and a baffle. In the preferred embodiment the combustion means was a powered burner comprising a venturi tube with venturi tube holes, and a woven ceramic fabric mantle containing the venturi tube. The baffle is made up of a spine, consecutive ribs attached to the spine, spine holes in the spine disposed between the ribs, and rib holes in the ribs, the rib holes being disposed in consecutive ribs on alternating sides of the spine. The blower section includes a blower communicating with the combustion chamber through a gas/air mixing chamber.

Abstract: A low NO.sub.x, integrated boiler-burner apparatus includes a horizontally fired, factory assembled package boiler having an inlet plenum and a furnace space is provided with a multi-nozzle burner (MNB) array including a plurality of vertically and horizontally spaced burner nozzles located at an entrance to the furnace space for supplying fuel for combustion into the furnace space. The MNB array distributes the heat of the combustion exhaust gases across the furnace space for minimizing NO.sub.x formation. One or more chill tube assemblies are located within the furnace space just downstream of the MNB array for rapidly reducing the temperature of the combustion exhaust gases. Alternatively, laterally perforated internal air duct assemblies can also be provided within the furnace space alone or in combination with the chill tube assemblies in various arrangements to provide staged air for completing combustion in the furnace space.

Abstract: A high-efficiency wall-mounted boiler utilizes air/fuel control via a servovalve for the gas responsive to pressure drops across air and gas orifices measured to a common downstream pressure. A ceramic burner is floatingly held against its gasket and seals the combustion chamber while the blower is of adjustable speed to allow load modulation.

Abstract: The present invention relates to a heating device for submersion within a tank of water to boil the water to produce steam, and for superheating the steam, comprising an outer sleeve; an inner sleeve partially disposed through the outer sleeve and having a proximal end, and a distal end in the form of an outlet port, the inner sleeve further defining a vapor chamber; a heating element disposed within the vapor chamber and in electrical communication with an external electrical power supply, the heating element adapted to produce heat in response to electrical energy from the power supply; a steam inlet tube extending outwardly from the inner tube and in fluid communication with the vapor chamber; and a one way valve disposed within the vapor chamber adjacent the outlet port, the valve adapted to selectively gate the flow of vapor from within the vapor chamber through the outlet port; wherein the heating device is configured to heat the water within the tank to a boil to produce steam, the steam inlet tube ada

Abstract: A flue baffle for use in a hot water tank flue through which flue gases from a burner chamber are discharged. The baffle is comprised of an elongated flat undulated metal strip having a securable flat upper end. The undulated metal strip is shaped to define a plurality of integrally formed, wave-shaped, deformations on opposed side portions of a central longitudinal axis thereof. A narrower undulated metal band is secured to the metal strip on opposed sides thereof and disposed substantially midway between the wave-shaped deformations on opposed sides of the flat metal strip. The upper end of the strip is adapted to retain the flue baffle axially within the flue to create turbulence and resistance to hot flue gases rising from the burner chamber to enhance heat exchange between the flue and a liquid being heated and in direct contact with an exterior surface of the flue.

Abstract: A hot water heater including a housing, a plurality of heat exchanging devices connected in series and disposed inside the housing at different elevations, a heat source disposed inside the housing at the bottom and controlled to heat water in the heat exchanging devices, a cold water pipe connected to the heat exchanging device at the topmost elevation to guide cold water through the heat exchanging devices, a hot water pipe connected to the heat exchanging device at the lowest elevation to guide hot water out of the heat exchanging devices, the heat exchanging devices having vertical air ducts for guiding hot air through the heat exchanging devices, the air ducts of one heat exchanging device at a higher elevation being not vertically in alignment with that of a next heat exchanging device at a lower elevation.

Abstract: Discloses a heat-insulating structure for combustion equipment of such a type that a burner element of combustion equipment is insertedly disposed at an installation opening of thermal equipment such as a boiler, with a view to simplified structure and enhanced workability. In combustion equipment (B) having a burner element (20) insertedly disposed at the installation opening (1) of the thermal equipment (A) via the support frame (30) a thermal insulator (50) flush with the burner element (20) on the thermal equipment (A) side is disposed between the installation opening (1) and the outer side face of the support frame (30).

Abstract: A heat activated flue damper actuator employing an assembly of shape memory alloy springs with linkages to a conventionally designed contemporary flue damper. The combination of the spring material, spring configuration and dimensions, linkage/fastening scheme to the flue damper shaft and placement in the water heater's heating chamber are all controlled to optimize the energy efficiency of a conventionally designed, pilot-lit or pilotless ignition, contemporary gas water heater.

Abstract: A pipestill heater capable of increasing heat efficiency without using a large-sized oxidizing agent heating unit. The pipestill heater includes a radiation section and a convection section for preheating process fluid by exhaust gas of an elevated temperature discharged through a gas discharge path. A combustion device including a combination of a burner and a heat exchanger is arranged on a furnace floor constituting a part of a furnace wall. The heat exchanger includes a regenerator heated by exhaust gas to heat an oxidizing agent and a duct structure including an oxidizing agent passage and an exhaust passage. The regenerator is rotated relative to both passages. Exhaust gas is guided through both a gas discharge path and an exhaust passage.

Abstract: An open hot-water heater includes a water tank; a hot-water overflow extending from the water tank; a faucet connected to the hot-water overflow; and a cold-water supply arrangement for introducing cold water into the water tank to refill the water tank and to drive hot water therefrom through the hot-water overflow. The cold-water supply arrangement includes a cold-water inlet coupled to the water tank and a cold-water discharge pipe connected to the cold-water inlet and having an outlet opening situated in the tank for introducing cold water into the tank. There is further provided a tank volume varying device and a valve assembly exposed to cold-water pressure prevailing in the cold-water inlet.

Abstract: A heat activated flue damper actuator employing an assembly of shape memory alloy springs with linkages to a conventionally designed contemporary flue damper. The combination of the spring material, spring configuration and dimensions, linkage/fastening scheme to the flue damper shaft and placement in the water heater's heating chamber are all controlled to optimize the energy efficiency of a conventionally designed, pilot-lit or pilotless ignition, contemporary gas water heater.

Abstract: A water and/or space heater is provided in which water is circulated to prevent the localized overheating or vaporization thereof.

Abstract: A single port, internal liquid heat exchange assembly for heating domestic water from a free-standing, low pressure wood fired boiler. A threaded manifold fastener retains the assembly in suspension within a single access port of a conventional water heater. An elongated manifold contains first and second coaxial flow columns which terminate at exposed inlet and outlet ports and communicate with each other within the manifold. Constructions are disclosed having concentric flow columns, convolute and expandable manifold walls, internal bypass ports, vibration dampeners, multi-ported flow transition zones and which may include a sacrificial anode.

Abstract: The invention is concerned with a gas hot water heater intended for installation in a wall and including a combustion chamber from which are guided heating gas tubings within a water-carrying housing. The housing is provided with connections for forward and rearward flow of water and an exhaust gas collecting chamber provided with connections for exhaust gas and condensate discharge. In the practice of the invention, a heating gas tubing passing from top to bottom through the water-carrying flat box-type housing is in the form of at least one pocket extending parallel to a broad rear wall of the housing. A water-cooled combustion chamber, disposed in an upper portion of the housing substantially corresponds, in plan view, to a flat rectangular cross-section of the housing. A burner insert opening of the combustion chamber is provided within or approximately within the plane of a front wall having a width corresponding to, and extending parallel with, a rear wall.

Abstract: A water heater comprising a tank adapted to hold water, a water outlet communicating with the tank, a water inlet communicating with the tank and communicable with the outlet independently of the tank, and a temperature responsive valve in the tank for permitting unrestricted communication of heated water in the tank with the water outlet when the water temperature in the tank is below a predetermined value, and for restricting communication of heated water in the tank with the water outlet when the water temperature in the tank is above the predetermined value.