A chimney assembly includes a cone assembly and a chimney. The cone assembly includes a wall forming a truncated cone having an outer surface, a first circumferential edge, and a second circumferential edge, a support flange extending from the outer surface, and a bottom wall extending between the second circumferential edge and including a burner aperture wall formed therethrough. The chimney includes an inner wall, an outer wall circumscribing the inner wall, a bottom chimney wall, and a plurality of tabs. The bottom chimney wall extends between a first cylinder formed by the inner wall and a second cylinder formed by the outer wall. The plurality of tabs extend from the inner wall toward a center of the first cylinder. The support flange rests on the plurality of tabs.