LATENT HEAT RECOVERY TYPE HEAT SOURCE MACHINE AND NEUTRALIZER

PROBLEM TO BE SOLVED: To provide a latent heat recovery type heat source machine that can prevent exhaust gas from leaking to outside through a drain discharge passage before sealed with water.SOLUTION: A latent heat recovery type heat source machine 3 includes: a combustion part 4; heat exchangers 6, 7 for recovering sensible heat and latent heat from exhaust gas from the combustion part 4; a drain recovery part 11 for recovering drain generated in the heat exchangers 6, 7; a drain discharge passage 13 for discharging the drain recovered by the drain recovery part 11 to outside; a water sealing part (neutralizer) 20 installed in the middle of the drain discharge passage 13; a water storage part 23 installed downstream of the water sealing part 20; and a sealing part 30 for sealing an outlet of the water storage part 23 and releasing the sealing with water pressure exceeding a predetermined value. Before a water sealing part 21 is sealed with the drain generated due to combustion after apparatus installation, the sealing by the sealing part 30 prevents leakage of exhaust gas, and after the water sealing is completed, the sealing is automatically released, so as to secure discharge of the drain.