JP2011214771A - Gas burner unit and gas water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas burner unit having a supporting structure of a low NOx burner and a suppressing section for suppressing flow of secondary air integrated with each other, and a gas water heater.SOLUTION: In this gas burner unit 16 including a bottomed burner case 35 in which the low NOx burners 10 are horizontally arranged with a very small clearance gap, and which has a front plate 81 having first and second openings 30, 98 respectively fitted to inlet ports 60a, 60b of first and second gases and air at a front side, a supporting member 90 for the low NOx burners 10 at a lower back side, and further a back plate 82 and side plates 83, 84 respectively at a back side and right and left both sides of the supporting member 90, the first and second suppressing sections 111, 131 for suppressing the flow of secondary air are respectively disposed on a forward projecting section 101 projecting forward and a backward projecting section 120 projecting backward to support the low NOx burners 10.

Description

The present invention relates to a gas burner unit and a gas water heater in which low NOx burners are arranged side by side.

In the gas burner unit described in Patent Document 1, a plurality of gas burners are arranged side by side in the left-right direction. Each gas burner is supported by a claw portion that engages with the front and rear portions sandwiched from both sides in the left-right direction.

JP 2006-266516 A

In this gas burner unit, an end space extending in the vertical direction is formed between the front upper side and the rear portion of the adjacent gas burners, and there is a flow of secondary air that goes upward from below in this end space. . For this reason, there is a risk that the flame is pulled by the flow of the secondary air and floats (so-called lift). Therefore, conventionally, a suppression portion is separately provided, and the flow of secondary air is suppressed by inserting the suppression portion into the end space.
The present invention has been made in view of such circumstances, and has a gas burner unit having a simple structure provided with a forward projecting portion and a rear projecting portion that serve both to support a low NOx burner and to suppress the flow of secondary air, and An object is to provide a gas water heater.

The gas burner unit according to the first aspect of the present invention is directed to the front and lower sides from the first and second gas and air inlets, and the upper part from the first and second gas and air inlets. Each has a flat flame outlet for releasing gas, and has burner forming members that form first, second, and third closed portions that close the bottom, rear, and front upper side, A low NOx burner partitioned in the front-rear and left-right directions by a plurality of partition plates, and the low NOx burner are arranged side by side in the left-right direction with a slight gap, and on the front side, the first and second gas and air A front plate having first and second openings respectively corresponding to the inlets; a support member for the low NOx burner on the lower rear side; and a rear side of the support member and on both left and right sides A bottomed burner case having a rear side plate and a lateral side plate, respectively. In the burner unit,
Supporting each low NOx burner to the burner case is as follows:
1) The first and second openings are burred on the rear side and are inserted into the first and second gas and air inlets,
2) A first notch is formed in the support member, and a rear side of the first closing portion is fitted into the first notch,
3) A second notch is formed in a forward projecting portion provided on the rear plate and projecting forward, and the upper side of the second closing portion is fitted into the second notch,
4) A third notch is formed in a rearward projecting portion provided on the front side plate and projecting backward, and the third notch is inserted into the third notch,
The forward projecting portion and the rear projecting portion are inserted into end spaces formed between the front upper portions and between the rear portions of the adjacent low NOx burners, respectively, and the end spaces are moved upward from the bottom. First and second suppression portions that suppress the flow of the secondary air are respectively provided.

In the gas burner unit according to the first aspect of the present invention, it is preferable that the rear side plate includes a heat shield portion provided on the forward projecting portion, and is integrally formed from a single metal plate.

In the gas burner unit according to the first invention, the forward projecting portion has a horizontal plate extending in the left-right direction with one surface facing upward,
An upper inclined plate inclined forward and downward from a front edge of the horizontal plate;
A lower inclined plate inclined downward and rearward from the front edge of the upper inclined plate,
The second notch and the first suppression portion can be formed in the upper inclined plate.

In the gas burner unit according to the first invention, it is preferable that the horizontal plate is provided with an air hole at a position corresponding to an intermediate position between the adjacent low NOx burners.

In the gas water heater according to the second aspect of the present invention, the first and second gas and air inlets are provided below the front part, and the first and second gas and air inlets are provided at the upper part. A low NOx burner having a flat flame outlet for discharging the gas, and the low NOx burner are arranged side by side with a gap between them, and the front side of the first and second gases and air A front plate having first and second openings respectively corresponding to the introduction ports; a support member for the low NOx burner on the lower rear side; and a rear plate on the rear side of the support member. A burner unit having a bottomed burner case, a primary heat exchanger provided on the burner unit and taking in combustion gas generated from the low NOx burner and heating water, and discharged from the primary heat exchanger Is supplied to the primary heat exchanger by the generated combustion gas. In gas water heater and a secondary heat exchanger for preheating water to,
Supporting each low NOx burner to the burner case is as follows:
1) The first and second openings are burred on the rear side and are inserted into the first and second gas and air inlets,
2) A first notch is formed in the support member, and the rear side of the bottom of the low NOx burner is fitted into the first notch,
3) A second notch is formed in a forward projecting portion provided in the rear side plate and projecting forward, and the upper side of the rear portion of the low NOx burner is fitted into the second notch,
4) A third notch is formed in a rearward projecting portion provided on the front side plate and projecting rearward, and the front side upper side of the low NOx burner is inserted into the third notch,
The forward projecting portion and the rear projecting portion are inserted into end spaces formed between the front upper portions and between the rear portions of the adjacent low NOx burners, respectively, and the end spaces are moved upward from the bottom. First and second suppression portions that suppress the flow of the secondary air are respectively provided.

The gas burner unit according to any one of claims 1 to 4 does not take the configuration of the present invention by providing a forward projecting portion and a rear projecting portion that serve both to support the low NOx burner and to suppress the flow of secondary air. It is possible to make the structure simpler than the case.

In particular, in the gas burner unit according to claims 2 and 3, since the rear side plate including the forward projecting portion and the heat shield portion is integrally formed from a single metal plate, it does not take the configuration of the present invention. It is also possible to have a robust structure.

In the gas burner unit according to the fourth aspect, since the air holes are provided in the horizontal plate, the heat shield portion can be cooled and the secondary air can be supplied.

In the gas water heater according to claim 5, the configuration of the present invention is provided by providing the gas burner unit with a forward projecting portion and a rear projecting portion that serve both to support the low NOx burner and to suppress the flow of secondary air. It is possible to make the structure simpler than the case where it is not taken.

It is an internal structure figure of the gas water heater which concerns on one embodiment of this invention. (A), (B) is the perspective view and top view of a gas burner unit which concern on one embodiment of this invention, respectively. It is a perspective view of a low NOx burner. (A), (B), (C) is the perspective view of a burner case, the elements on larger scale of the figure (A), and the perspective view of the burner case seen from the angle different from the figure (A), respectively. It is an internal structure figure of a burner case. It is the front view of a rear side board, a top view, and a side view.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIG. 1, the gas water heater 25 according to one embodiment of the present invention includes a gas burner unit 16, a primary heat exchanger 19, and a secondary heat exchanger 24.
The gas burner unit 16 is a low NOx burner 10 in which an air-fuel mixture obtained by mixing fuel gas and air supplied from a gas pipe 18 is arranged inside (see FIGS. 2, 3, 4, and 5). It is jetted upward to form a flame and generate combustion gas.
The gas burner unit 16 supplies the combustion gas to the primary heat exchanger 19 disposed on the upper part of the gas burner unit 16.

The primary heat exchanger 19 heats water by sensible heat of the combustion gas sent from the lower part to make hot water, sends the hot water to the mixing valve 20 and discharges the combustion gas from the upper part. The mixing valve 20 mixes the water flowing in through the water pipe 21 with the hot water produced in the primary heat exchanger 19 to produce hot water having a predetermined temperature, and supplies the hot water to the tapping pipe 22.
A fan 23 for supplying air into the gas burner unit 16 is fixed to the bottom of the gas burner unit 16.

On the primary heat exchanger 19, the secondary heat exchanger 24 which preheats the water supplied to the primary heat exchanger 19 with the combustion gas discharged | emitted from the primary heat exchanger 19 is arrange | positioned. Therefore, the gas water heater 25 having the gas burner unit 16, the primary heat exchanger 19, the secondary heat exchanger 24, and the like has the sensible heat of the combustion gas in the primary heat exchanger 19 and the latent heat of the combustion gas in the secondary heat exchanger 24. Can be efficiently used as a heat source for heating water. The water preheated by the secondary heat exchanger 24 is supplied from the water pipe 21.
The primary heat exchanger 19 is connected to a circulation circuit 27 through which water is circulated by the operation of a circulation pump 26 provided in the gas water heater 25. The primary heat exchanger 19 supplies hot water used for hot water supply. While heating, the water flowing through the circulation circuit 27 is heated and supplied to a bathtub or the like. Note that functional parts, members, and the like constituting the gas water heater 25 including the gas burner unit 16 are disposed and fixed in a box-shaped casing 28.

Next, the structure of the gas burner unit 16 will be described in detail. In the following description, the front side is the front, the back side is the rear, the left side is the left, and the right side is the right, with the first opening 30 shown in FIG.
As shown in FIGS. 2A and 2B, the gas burner unit 16 has a structure in which a burner case 35 is covered with an outer case 36. The outer case 36 is open at the front and upper surfaces. A front plate 81 of the burner case 35 is attached to an opening portion on the front surface of the outer case 36. In the figure, an electrode portion 47 for ignition and flame detection is attached to the front surface (front plate 81) of the gas burner unit 16 from the outside.
The rear and left and right side plates 38, 39, 40 of the outer case 36 are predetermined as heat shield plates 42, 43, 44 surrounding the combustion chamber of the burner case 35 (space formed above the low NOx burner 10), respectively. They are connected by a connecting piece 45 through a gap. In addition, the material of these heat shield plates 42, 43, 44 is stainless steel heat-resistant and oxidation-resistant steel.
Inside the burner case 35, the low NOx burners 10 are arranged side by side in the left-right direction with a slight gap. For convenience of explanation, only some of the low NOx burners 10 are shown in each figure. Moreover, the position or number of the low NOx burner 10 may not match each other throughout the drawings. Furthermore, the attachment structure may be omitted for the low NOx burner 10 (not shown).

Here, the low NOx burner 10 will be described.
As shown in FIG. 3, the low NOx burner 10 has a flat shape as a whole. Moreover, the bottom part, the rear part, and the front upper part of the low NOx burner 10 are formed thinner than the other bulged parts. For this reason, end spaces 55 and 56 extending in the vertical direction are formed between the upper front portion and the rear portion of the adjacent low NOx burners 10 (see FIG. 2B).
A first gas and air introduction port 60 a and a second gas and air introduction port 60 b are provided below the front portion of the low NOx burner 10. In addition, a flame outlet 61 is provided on the upper portion of the low NOx burner 10. From the flame port 61, a gas flow path in which the gas (air mixture) introduced from the first gas and air inlet 60a and the second gas and air inlet 60b is formed inside the low NOx burner 10. Erupts through. Specifically, the flame opening 61 is partitioned into a block shape in the front-rear and left-right directions by a plurality of partition plates 62.
The external shape of the low NOx burner 10 is formed by combining and welding the upper burner forming member 67a and the lower burner forming member 67b that are bent in half around the bent portions 65 and 66, respectively.
At the bottom, rear, and front upper side of the low NOx burner 10, the first closed part 51, the second closed part 53, and the third closed part are folded and closed at the ends of the burner forming members 67a and 67b. Each part 54 is formed.
A fixing cutout 70 is formed on the rear side of the first closing portion 51.

Next, the burner case 35 will be described in detail.
FIG. 4A shows a state where the outer case 36 is removed from the gas burner unit 16. 4B and 4C show a state in which the left heat shield plate 43 and the right heat shield plate 44 are further removed from the state shown in FIG. FIG. 5 shows a state in which the front heat shield 41 and the rear heat shield 42 are further removed from the states shown in FIGS. 4 (B) and 4 (C).

4 (A), (B), (C) and FIG. 5, the burner case 35 includes a bottom plate 80 at the bottom, and a front plate 81 extending upward from the front, rear, left and right sides with the bottom plate 80 as a bottom surface. , A box-shaped case surrounded by a rear side plate 82, a left side plate (horizontal side plate) 83, and a right side plate (horizontal side plate) 84, and the upper surface is open.
The bottom plate 80, the front side plate 81, the left side plate 83, and the right side plate 84 are integrally formed by bending a single metal plate.

As shown in FIG. 5, the bottom plate 80 is provided with a plurality of air holes 85 to introduce secondary air into the burner case 35 from below the bottom plate 80.
A support member 90 for supporting the rear side of the first closed portion 51 of the low NOx burner 10 is provided at the rear end portion of the bottom plate 80 (the lower rear side of the burner case 35). A plurality of first notches 91 are formed in the support member 90 at intervals corresponding to the arrangement intervals of the low NOx burners 10. The support piece 92 formed between the first cutouts 91 is formed with a support portion 93 extending upward from the base end, and a guide portion 94 extending upward from the distal end of the support portion 93 is formed. Yes. Of the first cutouts 91, the cutouts formed between the guide portions 94 are wider than the cutouts formed between the support portions 93. Therefore, when the rear side of the first closing part 51 is inserted into the first notch 91, the rear side of the first closing part 51 is guided by the guide part 94 and fits into the first notch 91. Fit. In detail, the notch 70 and the 1st notch 91 fit.
The guide portion 94 extends rearward and upward as described above, and also has a role of guiding and smoothly guiding the air supplied from the air hole 85 along the rear plate 82 side.

A plurality of first openings 30 and second openings 98 are formed in the lower portion of the front plate 81 at intervals corresponding to the arrangement intervals of the low NOx burners 10 in the left-right direction. Each opening is formed by burring, and the rising edge of the opening due to burring is directed backward. The first gas and air inlet 60a and the second gas and air inlet 60b of the low NOx burner 10 are fitted in these rising portions, respectively.
A step 99 is formed in the middle of the front plate 81. The step portion 99 is provided with a plurality of air holes 100 for introducing secondary air from the outside of the burner case 35 along the longitudinal direction of the step portion 99.
A heat shield plate 41 is provided inside the upper portion of the front side plate 81. The heat shield plate 41 will be described later.

As shown in FIG. 6, the rear side plate 82 includes a forward projecting portion 101 formed at an intermediate portion and a heat shield portion 102 formed at an upper portion, and is integrally formed from a single metal plate. . The rear side plate 82 is located on the rear side of the support member 90.
The forward projecting portion 101 projects forward and is formed along the left-right direction of the rear side plate 82. The forward projecting portion 101 includes a horizontal plate 105 extending in the left-right direction with one surface facing upward, an upper inclined plate 106 inclined forward and downward from a front edge of the horizontal plate 105, and a front edge of the upper inclined plate 106. And a lower inclined plate 107 inclined rearward and downward. The horizontal plate 105 is provided with a plurality of air holes 108 for introducing air into the combustion chamber at intervals corresponding to the arrangement intervals of the low NOx burners 10. The air hole 108 is disposed at a position corresponding to the middle in the left-right direction of the adjacent low NOx burner 10. The air supplied from the air holes 108 is used not only for cooling the heat shield 102 but also as secondary air. Note that the air supplied from the air holes 108 is guided mainly by the guide portion 94 located below the air holes 108.
A plurality of second notches 110 are formed in the upper inclined plate 106 at intervals corresponding to the arrangement intervals of the low NOx burners 10. The upper side of the second closing portion 53 is fitted into the second notch 110. Further, a first suppressing portion 111 is formed between the second notches 110. The first suppression unit 111 is inserted into the end space 56 (see FIG. 2B) from the rear side, and suppresses the flow of secondary air from the bottom to the top.
The heat shield 102 is formed to extend upward from the rear edge of the horizontal plate 105. A plurality of substantially conical protrusions 115 projecting rearward (outside of the burner case 35) are formed on the heat shield portion 102. When these protrusions 115 make point contact with the outer case 36 that covers the outside of the heat shield 102, a gap is secured and heat transmitted from the inner combustion chamber to the outer side is blocked. A connecting piece 45 is provided at the upper edge of the heat shield portion 102, and the rear side plate 82 is connected to the rear side plate 38 of the outer case 36.

The heat shield plate 41 provided inside the upper portion of the front plate 81 includes a rearward projecting portion 120 formed integrally therewith (see FIGS. 2B and 4B).
The front heat shield plate 41 is formed with a plurality of substantially conical projections 121 protruding forward (outside the burner case 35). When these protrusions 121 are in point contact with the burner case 35 covering the outside of the heat shield plate 41, a gap is secured, and heat transmitted from the inside combustion chamber to the outside is cut off. A connecting piece 45 is provided on the upper edge of the front heat shield plate 41, and the front heat shield plate 41 is connected to the front plate 81. In addition, the material of the heat shield plate 41 is stainless steel heat-resistant and oxidation-resistant steel, like the other heat shield plates 42, 43, and 44.

The rearward protrusion 120 has substantially the same shape as the forward protrusion 101. The rearward projecting portion 120 projects rearward and is formed along the left-right direction of the front side plate 81. The rearward projecting portion 120 includes a horizontal plate 125 extending in the left-right direction with one surface facing upward, an upper inclined plate 126 inclined rearward and downward from a rear edge of the horizontal plate 125, and a rear side of the upper inclined plate 126. A lower inclined plate (not shown) inclined forward and downward from the edge. The horizontal plate 125 is provided with a plurality of air holes 128 for introducing air into the combustion chamber at intervals corresponding to the arrangement intervals of the low NOx burners 10. The air hole 128 is disposed at a position corresponding to the middle in the left-right direction of the adjacent low NOx burner 10. The air supplied from the air holes 128 is used not only to cool the heat shield plate 41 but also as secondary air. Note that the air supplied from the air holes 128 is guided mainly from the air holes 100 (see FIG. 5) located below the air holes 128.
A plurality of third notches 130 (see FIG. 2B) are formed in the upper inclined plate 126 at intervals corresponding to the arrangement intervals of the low NOx burners 10. The third blocking portion 54 is fitted into the third notch 130. In addition, a second suppressing portion 131 is formed between the third cutouts 130. This 2nd suppression part 131 is inserted into the edge part space 55 (refer FIG. 2 (B)) from the upper side, and suppresses the flow of the secondary air which goes to the upper part from the bottom.

The left side plate 83 is formed with a first bent portion 135 whose rear end portion is bent in the right direction. The right side plate 84 is formed with a second bent portion 136 whose rear end portion is bent toward the left. The first and second bent portions 135 and 136 are provided with holes 137 and 138 through which screws 140 and 141 (see FIG. 4) for fastening the rear plate 82 are passed from the rear side, respectively.
Separate heat shield plates 43 and 44 are disposed above the left side plate 83 and the right side plate 84, respectively. A connecting piece 45 is provided on the upper edges of the heat shield plates 43 and 44, and the heat shield plates 43 and 44 are respectively mounted on the side plates 39 and 40 of the outer case 36 via the connecting pieces 45. Screwed to the container 19.

As described above, each low NOx burner 10 is supported on the burner case 35 by 1) the first and second openings 30 and 98 being burred on the rear side, and the first and second gas and air inlets. 2) The first notch 91 is formed in the support member 90, the notch 70 on the rear side of the first closing portion 51 is inserted, and 3) the second notch 110 is inserted. It is formed in the forward projecting portion 101 provided on the rear side plate 82, and the upper side of the second closing portion 53 is fitted therein. 4) The third notch 130 is formed in the rearward projecting portion 120 provided in the front side plate 81. This is done by inserting the third closing portion 54. That is, since each low NOx burner 10 is supported at four points, it is supported stably.

In addition, this invention is not limited to the above-mentioned embodiment, The change in the range which does not change the summary of this invention is possible.
In the above-described embodiment, the bottom plate 80, the front side plate 81, the left side plate 83, and the right side plate 84 are integrally formed by bending a single metal plate, but part or all of them are separated. You can also.

10: Low NOx burner, 16: Gas burner unit, 18: Gas pipe, 19: Primary heat exchanger, 20: Mixing valve, 21: Water pipe, 22: Hot water pipe, 23: Fan, 24: Secondary heat exchanger, 25: Gas water heater, 26: Circulation pump, 27: Circulation circuit, 28: Casing, 30: First opening, 35: Burner case, 36: Outer case, 38, 39, 40: Side plate, 41, 42, 43 44: heat shield plate, 45: connecting piece, 47: electrode portion, 51: first closing portion, 53: second closing portion, 54: third closing portion, 55, 56: end space, 60a : First gas and air inlet, 60b: Second gas and air inlet, 61: Flame port, 62: Partition plate, 65, 66: Bending part, 67a: Upper burner forming member, 67b: Lower Side burner forming member, 70: notch, 80: bottom plate, 81: front side plate, 8 : Rear side plate, 83: left side plate, 84: right side plate, 85: air hole, 90: support member, 91: first notch, 92: support piece, 93: support part, 94: guide part, 98: first 2 openings, 99: stepped part, 100: air hole, 101: forward projecting part, 102: heat shield part, 105: horizontal plate, 106: upper inclined plate, 107: lower inclined plate, 108: air hole, 110: 2nd notch, 111: 1st suppression part, 115: protrusion, 120: backward protrusion part, 121: protrusion, 125: horizontal plate, 126: upper inclined plate, 128: air hole, 130: 3rd cut Notch, 131: second suppressing portion, 135: first bent portion, 136: second bent portion, 137, 138: hole, 140, 141: screw

Claims (5)

The first and second gas and air inlets are formed on the lower front side, and the flat flame outlet for discharging the gas from the first and second gas and air inlets is formed on the upper part. Low NOx having burner forming members that form first, second, and third closing portions that close the bottom portion, the rear portion, and the upper front portion, and the flame opening is partitioned in the front-rear and left-right directions by a plurality of partition plates A burner and the low NOx burner are arranged side by side with a small gap in the left-right direction, and first and second openings that respectively correspond to the first and second gas and air inlets are provided on the front side. A bottomed burner case having a formed front side plate, a lower NOx burner supporting member on the lower rear side, and further a rear side plate and a lateral side plate on each of the rear side and the left and right sides of the supporting member; In the gas burner unit with
Supporting each low NOx burner to the burner case is as follows:
1) The first and second openings are burred on the rear side and are inserted into the first and second gas and air inlets,
2) A first notch is formed in the support member, and a rear side of the first closing portion is fitted into the first notch,
3) A second notch is formed in a forward projecting portion provided on the rear plate and projecting forward, and the upper side of the second closing portion is fitted into the second notch,
4) A third notch is formed in a rearward projecting portion provided on the front side plate and projecting backward, and the third notch is inserted into the third notch,
The forward projecting portion and the rear projecting portion are inserted into end spaces formed between the front upper portions and between the rear portions of the adjacent low NOx burners, respectively, and the end spaces are moved upward from the bottom. A gas burner unit characterized in that first and second suppression portions for suppressing the flow of secondary air are provided. 2. The gas burner unit according to claim 1, wherein the rear side plate includes a heat shield portion provided on the forward projecting portion, and is integrally formed from a single metal plate. . The gas burner unit according to claim 2,
The forward projecting portion is a horizontal plate extending in the left-right direction with one surface facing up,
An upper inclined plate inclined forward and downward from a front edge of the horizontal plate;
A lower inclined plate inclined downward and rearward from the front edge of the upper inclined plate,
The gas burner unit, wherein the second notch and the first suppression portion are formed in the upper inclined plate. 4. The gas burner unit according to claim 3, wherein an air hole is provided in the horizontal plate at a position corresponding to an intermediate position between the adjacent low NOx burners. The first and second gas and air inlets are formed below the front part, and the flat flame outlets for discharging the gas from the first and second gas and air inlets are formed on the upper part. The NOx burner and the low NOx burner are arranged side by side with a gap therebetween, and first and second openings respectively corresponding to the first and second gas and air inlets are formed on the front side. A burner unit having a front plate, a support member for the low NOx burner on the lower rear side, and a bottomed burner case having a rear plate on the rear side of the support member; and the burner unit A primary heat exchanger that takes in the combustion gas generated from the low NOx burner and heats the water, and water that is supplied to the primary heat exchanger by the combustion gas discharged from the primary heat exchanger Gas with secondary heat exchanger to preheat In hot water machine,
Supporting each low NOx burner to the burner case is as follows:
1) The first and second openings are burred on the rear side and are inserted into the first and second gas and air inlets,
2) A first notch is formed in the support member, and the rear side of the bottom of the low NOx burner is fitted into the first notch,
3) A second notch is formed in a forward projecting portion provided in the rear side plate and projecting forward, and the upper side of the rear portion of the low NOx burner is fitted into the second notch,
4) A third notch is formed in a rearward projecting portion provided on the front side plate and projecting rearward, and the front side upper side of the low NOx burner is inserted into the third notch,
The forward projecting portion and the rear projecting portion are inserted into end spaces formed between the front upper portions and between the rear portions of the adjacent low NOx burners, respectively, and the end spaces are moved upward from the bottom. A gas water heater, characterized in that first and second suppression portions for suppressing the flow of secondary air are provided.

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