Abstract: A thermostatic condensing gas water heater, comprising a burner; a first heat exchanger (7), a second heat exchanger (4), a water inlet pipe (10), and a water outlet pipe (9) provided in succession along the flow direction of the burnt flue gas; a controller; and a water flow channel connecting the first heat exchanger (7) and the second heat exchanger (4) in parallel between the water inlet pipe (10) and the water outlet pipe (9), wherein flow control valves (3, 5) capable of adjusting the water flow distribution of the first heat exchanger (7) and the second heat exchanger (4) are provided on the water flow channel and controlled by the controller.

Abstract: A gas hot water heating device and a system with heating function are disclosed. The device includes a combustion device (1), an inlet (E) and an outlet (G) of a hot water pipeline (2), an inlet (I) and an outlet (H) of a heating loop (3), and a water tank (4). The device also includes a first heat exchanger (5), a second heat exchanger (6) and a third heat exchanger (7). A flue gas outlet (1-2) of the combustion device (1) is connected with flue gas passages of the first heat exchanger (5) and the second heat exchanger (6) in order and in series. A first water flow passage (5-1) and a second water flow passage (5-2) are arranged in the first heat exchanger (5), and the water tank (4) and the first water flow passage (5-1) of the first heat exchanger (5) are communicated between the inlet (E) and the outlet (G) of the hot water pipeline (2) in series. The second heat exchanger (6) and the third heat exchanger (7) can exchange heat with water in the water tank (4).

Abstract: A condensing gas water heating device includes a frame, a main heat exchanger and a condensing heat exchanger. The frame, main heat exchanger, and a condensing heat exchanger all are made of stainless steel. The main heat exchanger and the condensing heat exchanger are integrally welded with the flue of the frame along the flue gas flow path to form a heat exchanger assembly. A condensed water collector is arranged between the main heat exchanger and the condensing heat exchanger. By welding the frame, main heat exchanger and condensing heat exchanger, which are made of stainless steel, into the integrally structured heat exchanger assembly, the present invention simplifies the structure and processing technology of the heat exchanger assembly, saves the installation space and materials of the heat exchanger assembly, and improves the corrosion resistance of the heat exchanger assembly.

Abstract: A method of assembling multiple low NOx burners (100), a low NOx burners (100) and a tankless gas-fired water heater (500) are disclosed. The method includes the step of assembling multiple bodies (152), each body (152) includes multiple first burner ports (135) connected to a first burner inlet (125) and multiple second burner ports (150) connected to a second burner inlet (140). The method also includes the step of selecting one of the bodies (152) and inserting a first inlet tube (120, 220, 320, 420) into the second burner inlet (140) to provide a fuel/air mixture to the second burner ports (150) at a first rate. The method also includes the step of selecting one of the bodies (152) and inserting a second inlet tube (120, 220, 320, 420) into the second burner inlet (140) to provide the fuel/air mixture to the second burner ports (150) at a second rate different from the first rate.

Abstract: A gas water heater includes a water tank, a combustion chamber, a burner, a heat exchanger tube at least partially within the water tank, and a fan. The burner receives fuel gas and primary air to create a primary air-fuel mixture for combustion in the combustion chamber with secondary air. The primary air-fuel mixture has a gas concentration above the upper explosive limit of the fuel gas. Secondary air is supplied to the combustion chamber through a secondary air conduit that is separate from the burner. The heat exchanger tube receives the products of combustion, transfers heat from the products of combustion to water in the tank, and exhausts of the products of combustion. Only air flows through the fan; no fuel-air mixture flows through the fan. The water heater utilizes partial premix combustion with low excess air ratio and low contaminant emission.