FIG. 1 is a front perspective view of the heater board enclosure;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right side elevation view thereof and a mirror image of the left side;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a bottom perspective view thereof.

The broken lines showing portions of the heater board enclosure are shown for illustrative purpose only and forms no part of the claimed design.