The heater comes with 4 fire bricks (230 mm x 115 mm x 38 mm) and a 480 mm long brick retainer as well as two triangular bricks (50 x 70 x 250 mm) for the front.
Place the four fire bricks upright, up against the rear wall of the firebox.
Place the U-shaped brick retainer over the top of the bricks such that the bricks fit inside the U-section. This will hold them in place.
Place the triangular firebricks at the front of the firebox beneath the door opening.
(Note: the firebricks may already be in place upon arrival of the new appliance.)