Two cycles in, and the towels are still damp. When your dryer takes too long to dry clothes, the usual cause is restricted airflow: lint in the vent, or a duct that is crushed, kinked or too long. Our techs test that first, at the outside vent, before they look at any part.

We don’t have a reliable percentage for how often each is the cause, but lint buildup is the more common of the two. Both are worth ruling out before you spend anything on parts. The vent test comes first below.

Test the Vent and Airflow First

Unplug the dryer before you move it, and leave the gas line alone on a gas model. Then test airflow before you take anything apart.

1. Run the dryer on a heat cycle and go outside to the exterior vent hood.
2. Check how much air is coming out. Weak airflow means something is restricting the duct.
3. Look at the hood flap. It should open freely, not sit stuck or blocked.
4. Back inside, unplug the dryer, pull it out and check the duct behind it for crushing, kinks and lint.

These are the blockages our techs find most: lint buildup, crushed or kinked ducts, and obstructed exterior flaps. They also trace the whole vent path to find where the air is being held up.

Run length is the other issue. The model building code (IRC) sets a default maximum of 10.7 m (35 ft) of duct from the dryer to the outside. Each 45° bend takes off 0.76 m (2.5 ft) and each 90° bend takes off 1.5 m (5 ft). The flexible duct right behind the dryer doesn’t count. Your dryer’s installation instructions can override that default. In our work, many standard 4-inch ducts top out around 7.6 m (25 ft), with less allowed for each elbow, and the exact limit varies by model. So check your manual. If your equivalent duct length is over the limit, or airflow stays weak after cleaning, we recommend rerouting the vent.

When a Dryer Takes Too Long to Dry Clothes: Is It a Fault?

A long cycle on its own doesn’t prove a fault. Drying time depends on load size, fabric type, the settings you pick and how well the dryer is maintained. A normal load that still takes more than 60 minutes after the lint screen and vent are clean is a fault, though.

At the end of the cycle, note two things. Are the clothes damp, and is the dryer hot or only warm? Write both down. They decide which checks come first, and a technician will ask. If the drum doesn’t turn at all, that’s a different fault, covered in our post on a drum that won’t turn.

Lint Screen, Load Size and Cycle Choice

These checks cost nothing, so do them before you buy a part.

1. Clean the lint screen after every load. A clogged screen restricts airflow, which lengthens drying times and raises energy use.
2. Hold the screen up to the light. Holes or tears let debris into the vent, so replace a damaged screen.
3. Vacuum the housing the screen sits in. Do it monthly.
4. If softener or detergent residue is clogging the mesh, scrub it with a nylon brush.
5. Run one smaller load of similar fabrics on a normal heat setting and time it.

Load size, fabric and settings all change drying time, so this last test tells you whether the dryer is slow or the load was.

Parts That Fail When the Vent Is Clear

With the vent clear, our techs check airflow, exhaust temperature and cycling behaviour first. Then they inspect the moisture sensor, the cycling thermostat and the heating system for faults.

On electric dryers, a partly failed heating element can cause weak heat. Restricted airflow or a faulty moisture sensor can cause the same slow drying, so the element isn’t a safe first guess. A fully burned-out element gives little or no heat. A blown thermal fuse mostly gives no heat or a dead dryer, so if heat is still there, airflow is the likelier cause.

You can’t see a bad thermal fuse. Only a multimeter continuity test confirms it, and a blown one can’t be reset. On gas models the fuse may cut the burner or ignition circuit. On electric models it may cut the heating or motor circuit. Unplug the dryer before any panel comes off. The testing is a job for someone with a multimeter and the training. For a wider walk through, see our dryer repair guide.

Breaker and Gas Problems That Look Like a Vent Problem

On an electric dryer, the breaker can be half tripped. It looks on, or nearly. The drum and motor can still run while the heating element, which needs the full 240V, doesn’t get full power. The usual sign is no heat at all, not slow drying, so it’s less likely if your dryer makes some heat. The check is free, though. Switch the breaker fully off, then back on, and make sure both poles are engaged. If it trips again, stop resetting it.

On a gas dryer, a fault in the gas supply is not a homeowner check. If you smell gas, go straight to the next section.

When to Stop and Call a Technician

Stop and call if you notice a gas smell, a burning smell, unusual heat from the cabinet or the outlet, damaged wiring, or a breaker that keeps tripping. Don’t run the dryer again to see whether the problem clears.

A gas smell means leaving. Don’t touch switches or use a phone inside the building. Clear everyone out and call the gas supplier, or the fire department if you can’t reach them. Gas work and 240V work belong to a qualified installer or service agency.

A clogged vent is also a fire matter. The NFPA found that “failure to clean” was the leading contributing factor in 33% of US home dryer fires in 2010 to 2014. That data doesn’t name a slow dryer as a warning sign, but it’s a reason not to leave a clogged vent alone.

If your dryer still takes too long to dry clothes after the free checks, contact us about dryer repair. Have your model number ready, and tell us what you’ve already done: the lint screen, the vent test at the hood and the breaker. Costs vary by model and fault, so ask for a quote.