The ornamental design for a fireplaceheater, as shown and described.
FIG. 1 is a front elevational view of the fireplace heater showing my new
design;
FIG. 2 is a plan view of FIG. 1;
FIG. 3 is a side elevational view taken from the right side of FIG. 1 on a
reduced scale, the left side being a mirror image of the right side shown
herein;
FIG. 4 is a rear elevational view of FIG. 1 on _a reduced scale; and
FIG. 5 is a bottom plan view of FIG. 1 on a reduced scale.