Dryer vent repair: costs, fixes and the code rules
Dryer vent repair costs $75 to $150 for a broken vent and $200 to $500 to reroute one, according to Fixr. Most repairs fix one of five problems: a plastic or foil hose, a crushed or disconnected duct, a broken hood or flap, a vent that ends indoors, or a run too long for the dryer to push air through. The rules for each come from section M1502 of the International Residential Code, the model code for houses; your state or city may amend it.
Common dryer vent repairs
Clothes dryer vent repair, dryer duct repair and dryer exhaust repair are the same work under different names: the duct is the vent. These are the problems it fixes.
| Problem | The fix | Code or source |
|---|---|---|
| Plastic or foil hose behind the dryer | Replace with a single listed transition duct, no longer than 8 feet, not hidden in a wall | IRC M1502.4.3 (UL 2158A); USFA; Whirlpool |
| Crushed or kinked duct | Replace the section; reposition the dryer so the hose is not pinched | USFA |
| Disconnected or sagging duct in a wall, attic or basement | Reconnect with the insert end pointing with the airflow, joints sealed and mechanically fastened, supports no more than 12 feet apart | IRC M1502.4.2 |
| Broken hood, flap or damper | Replace with a hood that has a backdraft damper, no screen, and an opening of at least 12.5 square inches | IRC M1502.3, M1502.3.1 |
| Vent ends in the attic, crawl space or wall | Extend it outside, at least 3 feet from openings into the house unless the dryer maker says otherwise | IRC M1502.3; USFA |
| Run too long, or too many elbows | Reroute to a shorter path, or use the dryer maker's longer rating or a listed power ventilator | IRC M1502.4.6 |
| Birds nesting in the hood | Clear the nest; fit a guard that keeps birds out without mesh across the opening | IRC M1502.3; USFA |
Dryer vent repair cost
| Job | Fixr | HomeGuide |
|---|---|---|
| Repair a broken dryer vent | $75 to $150 | not listed |
| Reroute a dryer vent | $200 to $500 | $200 to $500 |
| Bird guard installation | $30 to $100 | $30 to $100 |
| Inspection | $30 to $60 | $30 to $60 |
Fixr says rerouting costs vary with how hard the dryer is to reach, and that the main reason to reroute is a hose with several bends that does not run outside as it should. You can book a repair together with a dryer vent cleaning; prices for that are in the dryer vent cleaning cost guide.
The 35-foot rule, and how elbows count
Under IRC section M1502.4.6.1, a dryer exhaust duct can be at most 35 feet long, measured from the connection to the transition duct to the outlet. The transition hose does not count. Every elbow uses up part of that 35 feet:
- Transition duct: one listed piece, 8 feet at most, never hidden in a wall (M1502.4.3).
- Exhaust duct: 4-inch smooth metal (M1502.4.1), 35 feet at most minus an allowance per elbow (M1502.4.6.1).
- Outside hood: a backdraft damper and no screen (M1502.3).
| Fitting | Counts as |
|---|---|
| 4-inch radius mitered 45-degree elbow | 2 feet 6 inches |
| 4-inch radius mitered 90-degree elbow | 5 feet |
| 6-inch radius smooth 45-degree elbow | 1 foot |
| 6-inch radius smooth 90-degree elbow | 1 foot 9 inches |
| 8-inch radius smooth 45-degree elbow | 1 foot |
| 8-inch radius smooth 90-degree elbow | 1 foot 7 inches |
| 10-inch radius smooth 45-degree elbow | 9 inches |
| 10-inch radius smooth 90-degree elbow | 1 foot 6 inches |
Worked example: 20 feet of straight duct with two 4-inch radius mitered 90-degree elbows counts as 20 + 5 + 5 = 30 feet, which is inside the limit. The same run with smooth 6-inch radius elbows counts as 23 feet 6 inches.
Dryer vent length calculator
Over 35 feet is not automatically a violation. The code lets the dryer manufacturer's installation instructions set the length instead (M1502.4.6.2), or a listed dryer exhaust duct power ventilator (M1502.4.6.3). Whirlpool's venting specification, for example, says each of its models has a maximum rated vent length in its product literature. Where the equivalent length is over 35 feet, the code requires a permanent label within 6 feet of the duct connection stating the length (M1502.4.7).
Booster fans
The code says domestic booster fans shall not be installed in dryer exhaust systems (IRC M1502.4.5). What it does allow is a dryer exhaust duct power ventilator that conforms to UL 705, installed to its maker's instructions (M1502.4.4). Whirlpool says there is no UL classification for booster fans and it does not give recommendations for their use. If a company proposes a fan for a long run, ask whether it is a listed dryer exhaust power ventilator.
Who to call for dryer vent repair?
A dryer vent company handles most of this list: hoses, hoods, flaps, reconnections and reroutes. Fixr advises hiring an HVAC professional for repairs. For a gas dryer, the NFPA says the gas line and connection should be checked by a qualified professional. For a reroute through walls, ceilings or the roof, ask whether your city requires a permit. The code refers to a concealment inspection, where the code official is given the dryer's installation instructions (M1502.4.6.2).
Use the form below and we will send your request to a dryer vent company that serves your ZIP code.
Dryer vent repair: common questions
Who do you call for dryer vent repair?
Who to call to reroute dryer vent
Dryer vent repair cost
Clothes dryer vent repair
Dryer vent replacement service
Dryer vent repair and installation
Sources
- International Code Council, 2021 International Residential Code, Chapter 15, section M1502 Clothes dryer exhaust: codes.iccsafe.org
- Whirlpool, "Dryer venting specifications" (W11688180A): whirlpool.com
- U.S. Fire Administration, "Clothes Dryer Fires in Residential Buildings (2008 to 2010)", August 2012: usfa.fema.gov
- NFPA, "Clothes dryer safety" tip sheet: nfpa.org
- Fixr, "Dryer vent cleaning cost", updated January 31, 2025: fixr.com
- HomeGuide, "How much does dryer vent cleaning cost?", page dated April 29, 2024: homeguide.com