6 Things You Really Shouldn’t Put in a Clothes Dryer

Next time you feel like moving an entire washer load straight into the dryer, don’t be too quick to toss your clothes in and walk away. Not every item of clothing can withstand a high-heat (or even a low-heat) tumble dry without shrinking, stretching or falling apart.

As if that’s not scary enough, some dryer habits could put you on the hook for an expensive dryer repair, with average repair costs ranging from $100 to $430, according to HomeAdvisor.

Installing a new dryer can run anywhere from $300 to $2,000, according to the same source. Even worse, certain items can disintegrate while drying, building up and collecting lint that blocks the flow of air, causes excessive heat to build up and creates a fire risk, warns the U.S. Consumer Product Safety Commission.

There’s no need for you to learn your dryer lessons the hard way, though. Take a tumble through the following items to keep out of your dryer.

Clothing soiled with flammable substances

Putting fabrics stained with combustible substances such as gasoline, alcohol or finishing oils into the dryer could cause them to catch fire inside the dryer drum — even if they’ve already been cleaned in a washing machine — according to the Consumer Product Safety Commission.

Even after undergoing a wash, traces of oils and other flammable substances can remain on clothing or rags, emitting vapors that can ignite or explode when exposed to high heat in the dryer.

Rather than risking a house fire, hang clothing that’s been soiled with flammable substances outside to dry. If you prefer, you can also hang them in a well-ventilated room, away from heat sources.

Rubber-backed bath mats

Rubber-backed bath mats can fall apart, leaving rubber and fabric pieces in the dryer and “wreaking havoc” on the dryer system, says Scott Thomas, director of services for Dryer Vent Wizard, headquartered in Irving, Texas.

“Heat causes the rubber to disintegrate, and the pieces that aren’t able to pass through the lint screen break up, going through the motor and into the vent line,” says Thomas

Meanwhile, larger chunks of rubber provide lint and other vent-clogging materials something to grab onto, creating a snowball effect that grows and grows.

The rubber on a bath mat can begin coming apart as soon as the first time you dry it and get caught in the dryer’s internal components, such as the motor, warns Craig Anderson, owner of Appliance Analysts, an online appliance care and advice resource.

He notes that the motor is the most expensive part of a dryer to repair or replace.

Running shoes

Popping your running shoes into the dryer to tumble dry after a rainy-day run might seem like a quick way to ready them again for the road, sidewalk or running trails. When it comes to drying running shoes, however, it’s better to resist the urge for fast results.

“Not only will your shoes get beat up as they tumble around the dryer, but the heat can also cause your shoes to shrink,” according to athletic shoe giant Nike. “Since the perfect fit makes the difference between a supported run and a painful one, you don’t want to risk any change to the shape or fit of your shoes.”

High heat can also damage glue and other shoe components that must be handled with care.

Even if you dry running shoes on low heat, on a dryer rack, in a mesh bag or dangling from the inside of the door, they won’t last as long, says Nike.

Instead, Nike recommends spot cleaning running shoes first. After cleaning, unlace the shoes so they can breathe, remove the insoles and stuff each shoe with crumpled newspaper to soak up water and help keep their shape. You can also dry running shoes by hooking them to the grill of a floor or wall fan for a couple of hours.

Clothes containing spandex

Don’t ruin your stretchy gym clothes, bras and swimsuits by tumbling them on high heat in the dryer.

“Spandex and other elastic materials are great for wearing comfort, but they often don’t do that well in a dryer,” advises appliance manufacturer Electrolux. “The high temperatures can damage the material, breaking it down and ruining the shape of your clothes.”

If you must dry clothes with spandex quickly, Electrolux recommends drying them at the lowest temperature setting and removing the clothes while they’re still damp.

Comforters and duvets

Large comforters and duvets typically exceed a dryer’s capacity, forcing it to work too hard and overheat, says Anderson. And repeatedly drying bulky, oversized items in a home dryer can cause the dryer to overheat and fail in as little as six months, he says.

The easiest way to tell if the dryer is overworking is if you notice a burning smell, an unusual whirring or other unusual sounds that the dryer doesn’t normally make, he says.

“If you hear anything that you think sounds strange, stop the cycle and make sure the dryer isn’t overworking,” says Anderson.

Better yet, take large comforters, duvets and thick blankets to your local laundromat to be laundered in large-capacity washers and dryers.

Clothing covered in pet hair

If you regularly put clothing, blankets or bedding covered with pet hair in the clothes dryer, you could be in for a costly repair. The dryer lint screen stops only around 50% of fur and hair from going past, says Dryer Vent Wizard’s Thomas.

“These materials start to build up, causing the motor to overheat,” he says.

Hair and fur combined with lint can become large obstructions in the vent line, decreasing efficiency and creating a fire hazard.

“Fires can occur when lint builds up in the dryer or in the exhaust duct,” according to the Consumer Product Safety Commission. “Lint can block the flow of air, cause excessive heat build-up and result in a fire in some dryers.”

Pet hair on wet clothes can also run up your gas or electric bill by taking longer to dry. Dryers are designed to remove humidity from clothes, so if wet pet hair is clinging to fabric after being cleaned in the washing machine, the dryer will have a harder time drying the clothes.