How to Change Dryer Ducts

Remove the dryer's electrical plug from its wall receptacle.

Number each section of the old dryer duct with a permanent marker, starting at the dryer louver and working back toward the dryer's exhaust port. The numbers will identify each duct's placement. The dryer louver penetrates the exterior wall or roof and connects to the end of the dryer duct. Most dryer louvers use dampers that allow exhaust air out but will not let outside air in.

Loosen the clamp holding the old duct to the dryer's exhaust port, using the correct screwdriver type. Pull the old duct off the exhaust port.

Loosen the dryer duct's hanger straps, if equipped, using the correct screwdriver. Duct runs over 4 feet usually use hanging straps. Short duct runs do not need hanger straps.

Cut the metal-backed duct tape holding the sections of the old duct together with a utility knife. Disconnect each piece of the old dryer duct. Dryer ducts use metal-backed tape to seal and hold its joints together.

Measure the length of each piece of old dryer duct with a tape measure and transfer each length measurement to a new section of 4-inch round metal duct, using the permanent marker to place a measurement line at the appropriate spots. Copy the identification number from each piece of the old duct onto its respective piece of new duct, using the permanent marker.

Cut each new duct piece along its measurement line with aviation snips.

Insert the factory-crimped end of the new dryer duct with the "1" label into the dryer louver. Wrap a piece of metal-backed duct tape over the seam between the dryer duct and louver.

Install each additional piece of the new dryer duct, using the duct's identification numbers as a placement guide. Each duct's factory-crimped end slips into the previous duct's cut end. Seal each duct seam with the metal-backed duct tape.

Slip the last dryer duct over the dryer's exhaust port. Tighten the exhaust port's duct clamp with the screwdriver.

Wrap the duct hangers around the new dryer duct and tighten the hangers with the correct screwdriver.