Flame deflector for a water heater pilot burner

Abstract

A gas-fired water heater includes a pilot assembly that provides a pilot flame deflector. The pilot flame deflector causes the pilot flame to surround a hot junctions end of a thermopile. The flame deflector does not cover a cold junctions end of the thermopile, such that the cold junctions are ventilated. A temperature differential between the hot and cold junctions is increase by ventilating the cold junctions and surrounding the hot junctions with the pilot flame. The temperature differential is further increased by radiant and convective heat applied to the hot junctions as a result of the flame deflector.

1 . A pilot assembly for use with a water heater, the pilot assembly comprising:
 a pilot burner operable to burn a fuel-air mixture to create a pilot flame;   a thermopile including a plurality of thermocouples, each thermocouple including a hot junction spaced apart from a cold junction; and   a flame deflector positioned near the hot junctions;   wherein the pilot flame is directed toward the hot junctions;   wherein the flame deflector causes the pilot flame to contact the thermopile near the hot junctions around at least 270 degrees of a circumference of the thermopile; and   wherein the flame deflector does not cover the cold junctions of the thermopile, such that the cold junctions are ventilated to increase a temperature differential between the hot junctions and the cold junctions.   
     
     
         2 . The pilot assembly of  claim 1 , wherein the flame deflector directs radiant energy and convective heat energy from the pilot flame toward the hot junctions. 
     
     
         3 . The pilot assembly of  claim 1 , wherein the flame deflector causes the pilot flame to contact the thermopile near the hot junctions around 360 degrees of the circumference of the thermopile. 
     
     
         4 . The pilot assembly of  claim 1 , wherein the flame deflector extends from a base to a distal end and the distal end includes a downwardly directed tab. 
     
     
         5 . The pilot assembly of  claim 1 , wherein a gap is defined between the flame deflector and the thermopile such that the pilot flame fills the gap and contacts both the flame deflector and the thermopile. 
     
     
         6 . A method of retrofitting a gas-fired water heater having a pilot burner and a thermopile having hot junctions and cold junctions, the thermopile generating sufficient energy to open a supply valve to supply gaseous fuel to the pilot burner when a temperature differential between the hot junctions and cold junctions is at least at pilot burner threshold temperature differential, the method comprising the steps of:
 (a) installing a pilot flame deflector over the hot junctions;   (b) deflecting the pilot flame with the flame deflector such that the pilot flame covers at least 270 degrees of the hot junctions;   (c) avoiding positioning the flame deflector over the cold junctions such that the cold junctions are ventilated and such that the temperature differential between the hot junctions and cold junctions is enhanced; and   (d) achieving the pilot burner threshold temperature differential with less gas consumption compared to the water heater prior to installing the pilot flame deflector.   
     
     
         7 . The method of  claim 6 , wherein step (b) includes covering 360 degrees of the hot junctions with the pilot flame. 
     
     
         8 . The method of  claim 6 , wherein the pilot burner includes an original pilot burner orifice through which gaseous fuel flows for the pilot flame; the method further comprising the step of removing the original pilot burner and installing a replacement pilot burner having a smaller-diameter orifice than the original pilot burner orifice.