Abstract: A fuel-fired water heater is provided with a premixing type main burner and an associated pilot burner for igniting it. A specially designed protective system is operative to detect a flame flashback burning condition in the main burner and responsively shut down the water heater. In one embodiment thereof, the protective system uses main burner body heat to melt a portion of a fuel supply line connected to the pilot burner during a flame flashback condition in the main burner. Such melting responsively causes an associated fuel supply valve to close and terminate water heater operation. In a second protective system embodiment a normally closed pressure switch is opened, thereby shutting down the water heater, when the switch detects a pressure indicative of a flame flashback condition in the main burner.

Abstract: A fuel-fired water heater is provided with a premixing type main burner and an associated pilot burner for igniting it. A specially designed protective system is operative to detect a flame flashback burning condition in the main burner and responsively shut down the water heater. In one embodiment thereof, the protective system uses main burner body heat to melt a portion of a fuel supply line connected to the pilot burner during a flame flashback condition in the main burner. Such melting responsively causes an associated fuel supply valve to close and terminate water heater operation. In a second protective system embodiment a normally closed pressure switch is opened, thereby shutting down the water heater, when the switch detects a pressure indicative of a flame flashback condition in the main burner.

Abstract: A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. Illustratively, all of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner.

Abstract: A fuel-fired water heater is provided with a premixing type main burner and an associated pilot burner for igniting it. A specially designed protective system is operative to detect a flame flashback burning condition in the main burner and responsively shut down the water heater. In one embodiment thereof, the protective system uses main burner body heat to melt a portion of a fuel supply line connected to the pilot burner during a flame flashback condition in the main burner. Such melting responsively causes an associated fuel supply valve to close and terminate water heater operation. In a second protective system embodiment a normally closed pressure switch is opened, thereby shutting down the water heater, when the switch detects a pressure indicative of a flame flashback condition in the main burner.

Abstract: A radiant gas burner within the combustion chamber of a water heater has a pilot flame created using a cross-sectionally elongated raw fuel jet that impinges on an interior surface portion of a flame holding outer burner wall portion, representatively of a metal wire mesh material, and is mixed within the burner with combustion air delivered thereto from outside the combustion chamber. The resulting fuel/air mixture passes outwardly through the impinged upon mesh wall portion, which functions as a pilot flame stabilizing structure, and is ignited to form a pilot flame on the exterior of the burner body. A thermocouple portion of a clogging detection system senses a change in the pilot flame shape caused by particulate clogging of the metal mesh material and responsively terminates further gas supply to the water heater.

Abstract: A radiant burner within the combustion chamber of a fuel-fired water heater is supplied with primary and secondary combustion air from outside the combustion chamber. A flame-holding mesh section of the burner is protected from becoming unacceptably clogged by particulate matter in the primary combustion air by causing the incoming secondary combustion air to flow sequentially through a finer mesh section and a tapered duct which increases the velocity of the secondary combustion air before causing it to impinge upon and cool a temperature sensor connected to a controller. Clogging of the finer mesh section decreases the cooling of the temperature sensor, thereby causing the controller to terminate operation of the burner before it becomes unacceptably clogged.

Abstract: A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. Illustratively, all of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner.

Abstract: A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. All of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner. The pilot burner may be mounted on the main burner in a variety of locations thereon.

Abstract: A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. All of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner.

Abstract: A radiant gas burner within the combustion chamber of a water heater has a pilot flame created using a cross-sectionally elongated raw fuel jet that impinges on an interior surface portion of a flame holding outer burner wall portion, representatively of a metal wire mesh material, and is mixed within the burner with combustion air delivered thereto from outside the combustion chamber. The resulting fuel/air mixture passes outwardly through the impinged upon mesh wall portion, which functions as a pilot flame stabilizing structure, and is ignited to form a pilot flame on the exterior of the burner body. A thermocouple portion of a clogging detection system senses a change in the pilot flame shape caused by particulate clogging of the metal mesh material and responsively terminates further gas supply to the water heater.

Abstract: A fuel-fired water heater has main and pilot burners disposed in its combustion chamber. All of the primary combustion air utilized by the main and pilot burners during firing thereof is supplied thereto via an enclosed path extending to the burners from outside of the combustion chamber. A burner clogging detection system is operative to shut down further combustion, upon sensing a condition of the pilot burner flame indicative of a predetermined degree of pilot burner clogging, prior to the main burner being clogged to an unacceptable degree by particulate matter entrained in incoming combustion air being delivered to the main burner.

Abstract: A fuel-fired low NOx water heater extending along a vertical axis has a radiant fuel burner disposed in its combustion chamber. The entire burner combustion air quantity is delivered to the burner from outside the combustion chamber via a horizontally serpentined flow path extending through an internal portion of the water heater. This serpentined air inflow path configuration causes a substantial portion of particulate matter in the incoming combustion air to be removed therefrom before entering and potentially clogging the burner.

Abstract: A radiant gas burner within the combustion chamber of a water heater has a pilot flame created using a raw fuel jet that impinges on an interior surface portion of a flame holding outer burner wall portion, representatively of a metal wire mesh material, and is mixed within the burner with combustion air delivered thereto from outside the combustion chamber. The resulting fuel/air mixture passes outwardly through the impinged upon mesh wall portion, which functions as a pilot flame stabilizing structure, and is ignited to form a pilot flame on the exterior of the burner body. A thermocouple portion of a clogging detection system senses a change in the pilot flame shape caused by particulate clogging of the metal mesh material and responsively terminates further gas supply to the water heater.

Abstract: A fuel-fired low NOx water heater extending along a vertical axis has a radiant fuel burner disposed in its combustion chamber. The entire burner combustion air quantity is delivered to the burner from outside the combustion chamber via a horizontally serpentined flow path extending through an internal portion of the water heater. This serpentined air inflow path configuration causes a substantial portion of particulate matter in the incoming combustion air to be removed therefrom before entering and potentially clogging the burner.

Abstract: A radiant gas burner within the combustion chamber of a water heater has a pilot flame created using a raw fuel jet that impinges on an interior surface portion of a flame holding outer burner wall portion, representatively of a metal wire mesh material, and is mixed within the burner with combustion air delivered thereto from outside the combustion chamber. The resulting fuel/air mixture passes outwardly through the impinged upon mesh wall portion, which functions as a pilot flame stabilizing structure, and is ignited to form a pilot flame on the exterior of the burner body. A thermocouple portion of a clogging detection system senses a change in the pilot flame shape caused by particulate clogging of the metal mesh material and responsively terminates further gas supply to the water heater.