Who makes Reliabilt Doors

Actually, while Reliabilt doors is a Lowe's owned brand name,the manufacturers who build under that name, however,vary greatly. For example, RB garage doors are made by Amarr. RB patio doors are Jeld-Wen RB interior doors are manufactured by Masonite Inc. RB windows previously were Survivor, but when they went under, Atrium took over the slot. This, by the way, I can only say is true for the east. Different regions of the country have different suppliers who manufacture under the RB brand.

Reliabilt is a "private label" door built for Lowe's by Jeld-Wen.   As for the interior doors the same company makes the Masonite interior door for Home Depot and the Reliabilt door for Lowe's. They use the same UPCs on both brands of reliabilt doors