A pressure washer with an infrared burner for generating hot water comprising: a. a shell having a closed top with a vent, an open bottom, and side walls with inner and outer surfaces; b. a heat exchanger coil fitted inside said shell, said heat exchanger coil having a cold liquid inlet port and a hot liquid outlet port, and wherein said heat exchanger coil has an open inner space; c. a perforated rigid frame inserted into said open inner space of said heat exchanger coil, said perforated rigid frame is designed to provide a uniform flow of a gas through all its perforated surface, said perforated rigid frame having an open bottom, an inner surface area, an outer surface area, and an inner volume; d. a porous burner being a porous cover wrapped around said perforated rigid frame, wherein the outer surfaces of said porous burner are at a predefined distance with said heat exchanger coil, whereby said distance is determined by the BTU size of said infrared burner, size of said heat exchanger coil and experimental trials to obtain the lowest combustion emissions; e. a bottom plate; f. an air-fuel supply system attached to said bottom plate to supply an air-fuel mixture into said inner volume; g. an ignitor located close to the outer surface of said porous burner to ignite said gas that permeate through the porous burner forming an infrared radiating flame all over the porous burner, thereby uniformly heating the liquid flowing through said heat exchanger coil, and whereby said pressure washer produces hot water with a high heat exchanger efficiency and low combustion emissions and pollution by both infrared radiation and by having hot air go through said heat exchanger coil, the pressure washer being characterized in that the bottom plate is sealably attached to the bottom of said perforated rigid frame, thereby forming a closed volume inside said porous burner, said bottom plate being large enough to also receive said bottom of said shell. a. a shell having a closed top with a vent, an open bottom, and side walls with inner and outer surfaces; b. a heat exchanger coil fitted inside said shell, said heat exchanger coil having a cold liquid inlet port and a hot liquid outlet port, and wherein said heat exchanger coil has an open inner space; c. a perforated rigid frame inserted into said open inner space of said heat exchanger coil, said perforated rigid frame is designed to provide a uniform flow of a gas through all its perforated surface, said perforated rigid frame having an open bottom, an inner surface area, an outer surface area, and an inner volume; d. a porous burner being a porous cover wrapped around said perforated rigid frame, wherein the outer surfaces of said porous burner are at a predefined distance with said heat exchanger coil, whereby said distance is determined by the BTU size of said infrared burner, size of said heat exchanger coil and experimental trials to obtain the lowest combustion emissions; e. a bottom plate; f. an air-fuel supply system attached to said bottom plate to supply an air-fuel mixture into said inner volume; g. an ignitor located close to the outer surface of said porous burner to ignite said gas that permeate through the porous burner forming an infrared radiating flame all over the porous burner, thereby uniformly heating the liquid flowing through said heat exchanger coil, and whereby said pressure washer produces hot water with a high heat exchanger efficiency and low combustion emissions and pollution by both infrared radiation and by having hot air go through said heat exchanger coil,