Abstract: A water feeder controller for a boiler monitors a low water cutoff sensor in a boiler and uses a feed timer to feed water to the boiler for a predetermined feed period of time. The feed timer brings the water level in the boiler well above the low water cutoff sensor. The feed timer supplies water to the boiler only if the low water cutoff sensor continues to indicate a low water level for a delay period of time measured by a delay timer. A resettable display indicates the quantity of water supplied by the water feeder to the boiler based on a feed counter incremented during water feeding. A manual feed button allows water to be manually fed to the boiler. The quantity of water manually supplied to the boiler is also shown on the display. The feed timer and delay timer are preferably implemented in software in a microcontroller in the water feeder controller. A lockout loop in the software prevents overfeeding of water to the boiler in the event of a failure of the low water cutoff sensor.

Abstract: An apparatus comprising a switch, a fuse, and a sensor that is capable of detecting the presence of flammable vapors and responsively changing in resistance, wherein the sensor enables the switch to supply current to the fuse which opens to shut down an appliance burner. The fuse is connected in series with a control circuit that enables a gas valve to supply gas to the burner 65. The apparatus comprises a voltage divider circuit that includes the sensor, which upon exposure to flammable vapors, increases in resistance to provide a voltage input to the gate of a FET 100. The FET switches on and conducts a current that blows the fuse to interrupt the appliance burner control circuit and shut down burner operation.

Abstract: A knob adjustment device particularly for adjusting the temperature in valve units for water-heating apparatus. The device comprises a geared transmission interposed between the knob and an operating member of the valve unit in order to transmit a rotary movement to the member about its own axis as a result of a rotation of the knob. The geared transmission includes a reduction mechanism with a variable transmission ratio such that, for a first angular portion and a second angular portion of the rotation of the knob, the member is rotated with respective different transmission ratios (T1,T2).

Abstract: A steam generation apparatus is set forth including a housing; a boiler adapted to generate steam within the housing; a filler cap adapted to be removably coupled to the boiler; a first pressure relief device coupled to the boiler adapted to release steam at a first pressure level; and a second pressure relief device coupled to the boiler adapted to release the steam at a second pressure level, where the second pressure level is higher than the first pressure level, the first pressure relief device is incorporated into and is made to vent into the filler cap, and the second pressure relief device is made to vent internally to the housing.

Abstract: A gas-fired water heater is provided with a combustion shutoff system which precludes further combustion within the water heater's combustion chamber in response to a combustion temperature therein reaching a predetermined level correlated to and indicative of a predetermined, undesirably high concentration of carbon monoxide present in the combustion chamber. In various illustrated embodiments thereof, the combustion shutoff system is operative to terminate further combustion air inflow to the combustion chamber, or terminate further fuel flow to the burner portion of the water heater.

Abstract: A gas-fired water heater is provided with a combustion shutoff system which precludes further combustion within the water heater's combustion chamber in response to a combustion temperature therein reaching a predetermined level correlated to and indicative of a predetermined, undesirably high concentration of carbon monoxide present in the combustion chamber. In various illustrated embodiments thereof, the combustion shutoff system is operative to terminate further combustion air inflow to the combustion chamber, or terminate further fuel flow to the burner portion of the water heater.

Abstract: An apparatus for determining a density-compensated liquid level in a vessel containing a mixture of liquid and vapors comprises a temperature sensor which produces a signal that is proportional to the temperature of the mixture; and a processing apparatus that includes one or more pressure sensors that allow for a measurement of an operating pressure and a differential pressure between the mixture in the vessel and a constant reference leg. The processing apparatus further includes an integral microprocessor for calculating the respective specific gravities of the liquid and vapor portions of the mixture based on the operating pressure, and then computing the density-compensated liquid level in the vessel based on such calculations of specific gravity and the differential pressure.

Abstract: A thermal expansion arrester for positioning within the tank of a water heater comprises a rigid tube maintaining a compressible volume of gas between first and second closure members wherein at least one of the closure members comprises a piston that is slidably and sealingly secured within the tube. In a preferred embodiment both closure members comprise pistons held in the tube by crimping its ends. In an uncompressed state the pressure of the gas within the tube is sixty psig.

Abstract: An apparatus for combusting a fuel and air mixture within a combustion chamber, particularly a combustion chamber of a gaseous fuel fired water heater. A pressure relief void is intentionally formed so that a combustion chamber forms communication with a surrounding environment through a peripheral gap between the combustion chamber wall and a vessel wall of a vessel. During ignition, the pressure relief void allows pre-combustion fluid within the combustion chamber to escape through both the pressure relief void and the exhaust flue. The pressure relief void reduces or eliminates undesirable noise associated with start-up and operation of conventional water heater combustion chambers with premixed burner systems. The pressure relief void of this invention is sized large enough to relieve an ignition pressure pulse from the combustion chamber upon ignition and yet is sized small enough to prevent a combustion flame from passing through the pressure relief void during ignition.

Abstract: An apparatus comprising a switch, a fuse, and a sensor that is capable of detecting the presence of flammable vapors and responsively changing in resistance, wherein the sensor enables the switch to supply current to the fuse which opens to shut down an appliance burner. The fuse is connected in series with a control circuit that enables a gas valve to supply gas to the burner. 65 The apparatus comprises a voltage divider circuit that includes the sensor, which upon exposure to flammable vapors, increases in resistance to provide a voltage input to the gate of a FET 100. The FET switches on and conducts a current that blows the fuse to interrupt the appliance burner control circuit and shut down burner operation.

Abstract: Safety shutoff apparatus can close a valve using a pressure operable device coupled to and acting upon the valve. The proximal end of a pressure line is coupled to the pressure operable device for applying fluid pressure thereto in order to operate the pressure operable device. A soluble plug at the distal end of the pressure line can seal it in order to maintain pressure at the pressure operable device. By placing the soluble plug next to an object that is subject to leaking, the soluble plug can dissolve when a leak occurs and release the pressure in the pressure line. The released pressure results in closure of the valve when mechanical movement is produced by the pressure operable device in response to the release of pressure.

Abstract: A water heater is arranged with the hot water storage chamber R1 at the top and the combustion chamber R2 at the bottom within the body 11 which is a container. The combustion chamber R2 is equipped with the air supply inlet 13a, and the flame arrester 27 is provided at the air supply inlet 13a. Within the combustion chamber R2, the main burner 22 and the pilot burner 25 are provided, the changing state of flame of the pilot burner 25 is detected by the thermocouple 26, and a controller 41 closes an electromagnetic valve for opening and closing the main gas passage, stops the combustion of the main burner 22 as well, and rings the alarm 44. In a alternate embodiment, a sensor burner 60 is used as a safety device to detect a state of flame of the sensor burner and to shut off fuel to the main gas burner.

Abstract: Apparatus for automatically shutting off the water supply to a leaking water heater includes a water collecting tray positionable beneath the heater, a valve mechanism attachable to the tray, a float mechanism, and an action arm interactive between the float mechanism and valve mechanism. When water collects in the tray, the float mechanism rises, causing the action arm to trigger the release of a spring-urged component of the valve mechanism to discontinue flow of water to the heater.

Abstract: A gas-fired water heater is provided with a combustion shutoff system which precludes further combustion within the water heater's combustion chamber in response to a combustion temperature therein reaching a predetermined level correlated to and indicative of a predetermined, undesirably high concentration of carbon monoxide present in the combustion chamber. In various illustrated embodiments thereof, the combustion shutoff system is operative to terminate further combustion air inflow to the combustion chamber, or terminate further fuel flow to the burner portion of the water heater.

Abstract: A water heater control system that prevents the accumulation and accidental ignition of dangerous quantities of unwanted flammable vapors. The system intermittently generates a spark at a predetermined interval such that if unwanted flammable vapors are present, they are burned in a controlled manner. The system obviates the need for flammable vapor sensors.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: An explosion-proof hot water heater of the type having a gas-fired combustion chamber at a lower end of the inner tank is described. The combustion chamber is an unsealed chamber and has a sealed bottom wall and a fuel burner in the combustion chamber. Combustion air intake ports are provided about the combustion chamber above the sealed bottom wall. A support base supports the sealed bottom wall elevated from a support surface. Air intake openings are provided about the outer skin casing of the hot water tank and spaced a predetermined distance above the sealed bottom wall. Air passages communicate the air intake openings with the combustion air intake ports of the combustion chamber. A gas vapour sensor is secured in relation to the support base below the sealed bottom wall and is adapted to cause the burner to be shut off upon detection of explosive vapours with sufficient time delay before such vapours reach the combustion chamber.

Abstract: A latched, spring loaded valve having a water sensor and an activation mechanism shuts off water supply, when a water leak is detected, to specific application as cloths washing machines, dishwashing machines, sinks, toilets, and refrigerators equipped with ice makers. The shutoff valve system with leak detector has a sealing member movable with a valve body between an open position and a closed position wherein the sealing member blocks fluid flow.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: A fuel-fired power vented heating appliance, representatively a water heater, has, in its draft structure, a single thermal or other type of cutoff switch which serves the dual function of preventing (1) the creation of an unacceptably high level of carbon monoxide in the combustion chamber of the appliance, and (2) thermal damage to a PVC vent pipe portion of the draft structure. When triggered, the cutoff switch operates to terminate further firing of the appliance. In one illustrative embodiment of the appliance, this is achieved by preventing further combustion air flow to the appliance. In another illustrative embodiment of the appliance, it is achieved by terminating further fuel flow thereto.

Abstract: A fuel-fired natural draft water heater is provided with a self-powered, low NOx burner system in which a thermoelectric generator is positioned to be heated by the water heater's fuel burner during firing thereof and used to power an auxiliary combustion air fan which operates to supply to the burner system a quantity of combustion air in addition to that normally supplied by the natural draft of the water heater during operation thereof. The burner system is configured in a manner such that the water heater is operative even if either or both of the thermoelectric generator and the auxiliary combustion air fan fail to function.

Abstract: The invention relates to a holding tube for a heat treatment plant using injection heating. The holding tube includes a first, fixed section consisting of a conduit (5) of predetermined length and a constant counter pressure valve (6). The holding tube also includes a second, adjustable section. The second, adjustable section consists of a cyclone (7) and an inclining conduit (10) of a predetermined length. In the inclining conduit (10) there is disposed a device (28) for maintaining a defined liquid level in the conduit (10).

Abstract: A method and apparatus for combusting a fuel and air mixture within a combustion chamber, particularly a combustion chamber of a gaseous fuel fired water heater. A pressure relief void is intentionally formed so that a combustion chamber forms communication with a surrounding environment through means other than the exhaust flue and/or a fuel and/or air inlet. During ignition, the pressure relief void allows pre-combustion fluid within the combustion chamber to escape through both the pressure relief void and the exhaust flue. The pressure relief void reduces or eliminates undesirable noise associated with start-up and operation of conventional water heater combustion chambers with premixed burner systems. The pressure relief void of this invention is preferably sized large enough to relieve an ignition pressure pulse from the combustion chamber upon ignition and yet is sized small enough to prevent a combustion flame from passing through the pressure relief void during ignition and/or operational combustion.

Abstract: A knob adjustment device, particularly for adjusting the temperature in valve units of a water-heating apparatus. The knob adjustment device is mounted so as to be rotatable about a rotation axis in a stationary housing of the valve unit and has a safety member for the unidirectional restraint of the knob adjustment device relative to the housing so as to oppose rotation of the knob adjustment device in a first direction of rotation about the axis, the knob adjustment device being free to rotate in the opposite direction of rotation.

Abstract: A bracket for use in mounting a safety switch in series with a thermocouple provides improved positioning of the switch to detect conditions causing safety concerns. The bracket includes adjustable support members for providing connection of the safety switch to a thermocouple and maintaining the position of the safety switch for improved detection. The bracket provides for mounting the safety switch connected in series to the thermocouple within a water heater for detection of overheat conditions.

Abstract: A safety device for shutting off the flow of gas to a gas-fired appliance in the presence of flammable vapors. The resistance of a variable resistance flammable vapor sensor is monitored by a microprocessor that controls the operation of a gas flow valve. When the measured resistance indicates the presence of a preselected concentration of flammable vapors, the gas flow valve is shut of and the ignition system cannot be energized.

Abstract: A bracket for use in mounting a safety switch in series with a thermocouple provides improved positioning of the switch to detect conditions causing safety concerns. The bracket includes adjustable support members for providing connection of the safety switch to a thermocouple and maintaining the position of the safety switch for improved detection. The bracket provides for mounting the safety switch connected in series to the thermocouple within a water heater for detection of overheat conditions.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: A knob adjustment device, particularly for adjusting the temperature in valve units of water-heating apparatus is described. The knob device is mounted so as to be rotatable about a rotation axis in a stationary housing of the valve unit and comprises safety means for the unidirectional restraint of the knob relative to the housing so as to oppose rotation of the knob in a first direction of rotation about the said axis, the knob being free to rotate in the opposite direction of rotation.

Abstract: A fluid safety discharge system for a relief valve having an inlet and an outlet includes a bushing frictionally engaging the relief valve outlet. The relief valve outlet is internally threaded for engaging with a threaded device, such as a discharge line. The bushing may contain a separate body and engagement region for use with hard-plumbed discharge lines. Optionally, an adapter may be used for retrofitting the bushing to an existing relief valve.

Abstract: A highly efficient flame arrester adapted for use in preventing an external flame from backflashing upstream in a pipe, or a conduit, or a stream carrying a flammable substance. The flame arrester comprises a contained layer of nested ellipsoids formed from expanded metal sheets made from magnesium alloy foil. The arrester is useful in fuel tanks, combustion systems, sea-going tankers, hot water or space heaters, and the like.

Abstract: A water feeder controller for a boiler monitors a low water cutoff sensor in a boiler and uses a feed timer to feed water to the boiler for a predetermined feed period of time. The feed timer brings the water level in the boiler well above the low water cutoff sensor. The feed timer supplies water to the boiler only if the low water cutoff sensor continues to indicate a low water level for a delay period of time measured by a delay timer. A resettable display indicates the quantity of water supplied by the water feeder to the boiler based on a feed counter incremented during water feeding. A manual feed button allows water to be manually fed to the boiler. The quantity of water manually supplied to the boiler is also shown on the display. The feed timer and delay timer are preferably implemented in software in a microcontroller in the water feeder controller. A lockout loop in the software prevents overfeeding of water to the boiler in the event of a failure of the low water cutoff sensor.

Abstract: A device for sensing a dangerous condition includes a sensor that provides a signal when a dangerous condition is sensed by the sensor. A power source is provided which is in communication with the sensor. The power source supplies the sensor with power. A trigger is provided which is in communication with the sensor. The trigger is activated by the signal to prevent the dangerous condition from producing a harmful effect. In one embodiment of the invention the power source is a thermoelectric power supply and the sensor is a self calibrating sensor.

Abstract: A fuel-fired heating apparatus, representatively a forced draft or natural draft gas-fired water heater having a combustion chamber, is provided with a flammable vapor control system that functions, during firing of the apparatus, to substantially prevent entry into and combustion within the combustion chamber of extraneous flammable vapors externally adjacent the bottom of the apparatus, without detecting the extraneous flammable vapors or terminating firing of the apparatus. The flammable vapor control system includes a dilution air flow passage connected to a discharge portion of the apparatus vent structure and having an inlet externally adjacent a bottom portion of the apparatus and operative to draw dilution air and extraneous flammable vapors into the vent structure discharge portion, and a combustion air flow passage having an inlet disposed adjacent the upper end of the apparatus, and an outlet communicated with the interior of the combustion chamber.

Abstract: A device for sensing a dangerous condition includes a sensor that provides a signal when a dangerous condition is sensed by the sensor. A power source is provided which is in communication with the sensor. The power source supplies the sensor with power. A trigger is provided which is in communication with the sensor. The trigger is activated by the signal to prevent the dangerous condition from producing a harmful effect. In one embodiment of the invention the power source is a thermoelectric power supply and the sensor is a self calibrating sensor.

Abstract: Combustible vapors from flammable materials spilled near a gas water heater can enter the water heater's combustion chamber and cause a serious fire or explosion. This problem can be avoided by ensuring that all combustion air is supplied from at least some selected distance (preferably eighteen inches or more) above a floor on which the water heater is placed. One version of the invention provides a flanged tube that can be installed so that an upper, inlet, end of the tube is above the selected height and so that the lower, outlet, end of the tube is sealed over a pilot flame access doorway. Various materials, such as an aerosol sealant foam or a flexible tape, are used to seal all other air inlets to the water heater.

Abstract: A water heater having a barrier for forming an enclosure around a lower portion of heater. The barrier has an inside wall, an outside wall and a space between the inside and outside walls. There is a skirt disposed within the barrier for slidably receiving the water heater tank. The burner for the water heater is disposed within the skirt. The outside wall of the barrier has at least one aperture for air to pass into the space. The inside wall has a plurality of ventilation holes to allow heat currents to escape through the space and causes a siphoning effect, thus preventing any fumes from reaching the flame. There is an outwardly extending flange surrounding a top edge of the barrier. The flange has an inside wall connected to the inside wall of the barrier, an outside wall connected to the outside wall of the barrier, and a space between the inside and outside walls that communicates with the space in the barrier.

Abstract: A water heater is arranged with the hot water storage chamber R1 at the top and the combustion chamber R2 at the bottom within the body 11 which is a container. The combustion chamber R2 is equipped with the air supply inlet 13a, and the flame arrester 27 is provided at the air supply inlet 13a. Within the combustion chamber R2, the main burner 22 and the pilot burner 25 are provided, the changing state of flame of the pilot burner 25 is detected by the thermocouple 26, and a controller 41 closes an electromagnetic valve for opening and closing the main gas passage, stops the combustion of the main burner 22 as well, and rings the alarm 44. In an alternate embodiment, a sensor burner 60 is used as a safety device to detect a state of flame of the sensor burner and to shut off fuel to the main gas burner.

Abstract: An apparatus for automatically shutting off a water supply to a leaking water heater includes a water-collecting tray adapted to be positioned beneath a water heater, and a float mechanism removably attachable to the tray. The float mechanism has a float adapted to reside within the tray. An arm extends from the float, and terminates in a trigger extremity located outside the tray. The trigger extremity is positioned to push upwardly upon a holding block that secures an extremity of a coil spring. The holding block also secures a tether that extends to an operating lever of a water shut-off valve. When the float rises in the tank, it causes the trigger extremity to release the coil spring in tensioned state from the holding block. Such action pulls the operating lever downwardly, causing shut-off of the water supply.

Abstract: A main burner 22, a pilot burner 25, and a lead-in pipe 29 supplying combustion exhaust to the pilot burner 25 are arranged in a combustion chamber R2. A flame arrester 27 with small holes 27a is provided at a bottom plate 13. Furthermore, a primary thermocouple 26 detecting the flame state of the pilot burner 25 and a secondary thermocouple 28 detecting the temperature in the combustion chamber R2 are connected in series but with opposite polarities. When the flame arrester 27 clogs up with fine particles, the pilot burner 25, which sucks in combustion exhaust, performs abnormal combustion before the main burner 22, which is detected by the primary thermocouple 26 and the secondary thermocouple 28, whereupon the combustion with the main burner 22 is stopped. Thus, incomplete combustion due to blocking of the air supply path can be prevented.

Abstract: The flow rate of water into a pressurised steam boiler heated by a burner is controlled by monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler and monitoring the firing rate of the boiler. The level of water in the boiler is measured by a pair of capacitance probes. By controlling the water flow with regard not only to variables relating to the boiler but also variables relating to the burner, it is possible to provide a better control of water flow. Also, by assessing variables relating both to the burner operation and the boiler operation, an assessment of the mass flow rate of steam from the boiler can be made without employing a steam flow meter.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. During firing of the water heater a combustion air shutoff system having a heat-frangible temperature sensing structure disposed within the combustion chamber senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner s structure within the combustion chamber. During firing of the water heater a combustion air shutoff system senses an undesirable temperature increase in the combustion chamber, caused by for example a partial blockage of the flow path, and responsively terminates further air flow into the combustion chamber, thereby shutting down the burner, prior to the creation in the combustion chamber of a predetermined elevated concentration of carbon monoxide.

Abstract: Envisioned at a moment when energy efficient use of natural gas or propane is considered essential to human needs and environment, this device is designed to increase the efficiency of gas-fired-hot-water-tanks. This major household appliance, widely used in North America represents a moderate to heavy consumption of energy. It addresses the problem of heat loss incurred in virtually all domestic hot-water-tank systems. In effect it is the same as closing the vent on a fireplace after the fire is out to prevent the fire created draft from sucking the air from the room. This device prevents air from randomly reaching the flame chamber, controlling it instead. It allows the flame to function as normal, but closes naturally when flame is off, effectively reducing air flow and subsequent heat loss, which would otherwise have continuous negative effect.

Abstract: A main burner 22, a pilot burner 25, and a lead-in pipe 29 supplying combustion exhaust to the pilot burner 25 are arranged in a combustion chamber R2. A flame arrester 27 with small holes 27 a is provided at a bottom plate 13. Furthermore, a primary thermocouple 26 detecting the flame state of the pilot burner 25 and a secondary thermocouple 28 detecting the temperature in the combustion chamber R2 are connected in series but with opposite polarities. When the flame arrester 27 clogs up with fine particles, the pilot burner 25, which sucks in combustion exhaust, performs abnormal combustion before the main burner 22, which is detected by the primary thermocouple 26 and the secondary thermocouple 28, whereupon the combustion with the main burner 22 is stopped. Thus, incomplete combustion due to blocking of the air supply path can be prevented.

Abstract: The flow rate of water into a pressurized steam boiler heated by a burner is controlled by monitoring the level of water in the boiler, monitoring the pressure of steam in the boiler and monitoring the firing rate of the boiler. The level of water in the boiler is measured by a pair of capacitance probes. By controlling the water flow with regard not only to variables relating to the boiler but also variables relating to the burner, it is possible to provide a better control of water flow. Also, by assessing variables relating both to the burner operation and the boiler operation, an assessment of the mass flow rate of steam from the boiler can be made without employing a steam flow meter.

Abstract: A flammable vapor detector is used to detect flammable vapors in the event of a volatile organic liquid spill near a gas fired appliance, such as a hot water heater. The appliance is mounted at an elevation above the floor while the detector is mounted at or near the floor where the spill may occur. The detector is connected electrically to a safety gas cut-off solenoid valve in the appliance to urge the valve to cut-off the flow of gas to the appliance in the event that the detector detects flammable vapor. Because the detector is below elevation of the appliance, the detector reacts to higher concentrations of flammable vapors than the concentrations of flammable vapors at the higher elevation of the appliance to turn off the gas to the appliance before the combustion air to the appliance reaches a lower flammability limit. The appliance used to describe the invention is a gas fired hot water heater.

Abstract: A water heater including a water container, a combustion chamber adjacent the container, the combustion chamber having a side wall and at least one flame arrestor to admit air and extraneous fumes into the combustion chamber and confine ignition and combustion of the extraneous fumes within the combustion chamber, and a burner having a multiplicity of burner ports associated with the combustion chamber and arranged to combust fuel to heat water in the container, and an air diverter including a baffle plate with an upper surface and an outer edge portion, the diverter positioned in the combustion chamber and having a lower portion of the upper surface positioned at about the same height as at least a portion of the burner ports, the baffle plate sized to form a gap between the outer edge portion and the side wall such that flames generated by combustion of the fuel tend to attach to at least a portion of the lower portion, and a flange attached to and angled upwardly from the outer edge portion and adapted to