To facilitate maintenance inspection of devices housed in a housing of a CO2 water heater, to reduce manufacturing cost of the housing, and to reduce the occurrence of damage and rust of a side panel.
A housing 12 is partitioned into a continuous maintenance area 36 facing a front 12a and a rear 12b and forming a wide width area and an initial maintenance area 38 forming a narrow width area. Panel plates 64, 72 shielding the front 12a and the rear 12b of the continuous maintenance area 36, and to panel plates 76, 78 shielding the front and the rear of the initial maintenance area 38, a side panel plate 28 shielding a housing side face adjacent to the initial maintenance area 38 is detachably attached. An attachment structure of the panel plates eliminates bolt connection as much as possible to thereby suppress the occurrence of damage by a bolt and rust from a damaged part.
MITSUMOTO YUKI
KATAOKA MASAKI
