Heater

FIG. 1 is a top front perspective view of a first embodiment of a heater;

FIG. 2 is a bottom front perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side perspective view;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a top plan view thereof.

The broken lines depict portions of the heater that form no part of the claimed design. The dash-dot-dash lines depict the boundary between the lower portion of the heater that forms the claimed design and the upper portion of the heater that form no part of the claimed design.