The ornamental design for the outdoor unit for water heater, as shown and described.
FIG. 1 is a front perspective view of the front, right, and top sides of an outdoor unit for water heater showing our new design;
FIG. 2 is a rear perspective view of the rear, left, and top sides thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom view thereof.
The broken line showing the outdoor unit for water heater is included for the purpose of illustrating portions of the outdoor unit for water heater and forms no part of the claimed design.