We claim the ornamental design for a heater, as shown and described.
FIG. 1 is a perspective view of an ornamental design for a heater;
FIG. 2 is front side view of the heater shown in FIG. 1.
FIG. 3 is a perspective view of a heater according to an embodiment of the invention.
FIG. 4 is an enlarged view of a portion of FIG. 3.
FIG. 5 is a front side view of the heater shown in FIG. 3.
FIG. 6 is a perspective view of a heater according to an embodiment of the invention.
FIG. 7 is a front side view of the heater shown in FIG. 6.
FIG. 8 is a perspective view of a heater accordingly to an embodiment of the invention.
FIG. 9 is a front side view of the heater shown in FIG. 8.
FIG. 10 is a rear side view of the heater shown in FIG. 8.
FIG. 11 is a top side view of the heater shown in FIG. 8.
FIG. 12 is a bottom side view of the heater shown in FIG. 8.
FIG. 13 is a right side view of the heater shown in FIG. 8; and,
FIG. 14 is a left side view of the heater shown in FIG. 8.
The broken lines depict portions of the heater and form no part of the claim. The surface in FIGS. 1 and 2 that is stippled illustrates a surface with a first color and the unstippled surfaces illustrate surfaces with a color different than the first color.