Signs showing the need for dryer duct repair include increased drying times for clothes, lint deposits on clothing and a burning smell, while operating the dryer. If clothes or the dryer feel very hot after one cycle, this is a sign that the duct needs repair.
Clogging of the dryer duct leads to increased drying times for clothes. Heavier clothing, such as jeans, sweaters or towels, will feel moist even after a cycle or two in the dryer. A clogged dryer duct prevents the flow of air and moisture out of the dryer, making it difficult for the clothing to dry. This leads to increased energy use and damage to clothing.
Problems in the dryer duct will often lead to overheating of the entire appliance, which can reduce the dryer's life. A dryer duct that needs repair will also create a burning odor, while the dryer is in use. Lint can clog up the dryer duct and catch fire, if the temperatures are too high. This is a dangerous sign and could lead to a fire, if the dryer duct is not repaired immediately.
If the duct hood flap fails to open normally, this can be a sign of a clogged duct that needs repair. Dryer ducts require cleaning annually. Repair is necessary, if any of the above signs are present and the duct has not been cleaned for a long time.