Customer Questions and Answers for Dryer Timer by Whirlpool

Hello Kevin,
This is an indication that there is a ducting issue. You see, the unit is not designed to have much back pressure from the ducting. When there is a ducting restriction, (crimp, clog, or excessively long duct), the heat, lint, and moisture are blown past the drum seals which are made of felt, right back into the cabinet of the unit where it is circulated back across the clothes. Due to the fact that the unit is sensing the moisture, it continues to run because the moisture is trapped in the unit and cannot escape. Correcting the ducting will normally correct this issue without any parts for the dryer being necessary.