The ornamental design for a gas heater, as shown and described.
Description:
FIG. 1 is a front view of the gas heater showing my new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a view of one side thereof;
FIG. 4 is a view of the opposite side thereof;
FIG. 5 is a perspective view showing the top and front thereof.
The pattern of perforations which is fragmentarily shown in FIG. 1 is understood to repeat uniformly and continuously across the entire indicated area.
