RV Tank Water Heater

FIG. 1 is a front, right, top perspective view of an RV tank water heater showing our new design; FIG. 2 is a front, left, top perspective view thereof; FIG. 3 is a front view thereof; FIG. 4 is a left view thereof; FIG. 5 is a right view thereof; FIG. 6 is a top view thereof; and, FIG. 7 is a bottom view thereof. The back view is omitted. The broken lines shown in the figures depict portions of the RV tank water heater that do not form part of the claimed design.