Two complaints tend to get lumped together: "the dryer isn't heating" and "the dryer takes forever." They're different problems. One is a missing flame or a failed element. The other is almost always about air, and the fix is often in the duct rather than the dryer.
Spend two minutes figuring out which one you have. It changes everything that follows.
No heat at all, or heat that isn't doing the job?
Start a timed dry cycle with a few damp towels and open the door after five minutes. Put your hand on the towels and the inside of the drum.
- •Cold or barely warm: the dryer isn't producing heat. Skip ahead to the no-heat section.
- •Warm or hot, but the towels are still wet at the end of a normal cycle: the heat is there and the moisture can't get out. Start with airflow.
Safety first
- •Unplug an electric dryer, or switch off both breakers for it, before removing any panel.
- •For a gas dryer, unplug it and close the gas shutoff valve behind it before moving it.
- •If you ever smell gas, don't touch light switches or plugs. Get everyone out, then phone Washington Gas or 911 once you're outdoors.
- •Never run a dryer with the lint screen removed.
When there's heat but the clothes stay damp
The lint screen
Pull it out and hold it under the tap. If water beads up and sits on the mesh instead of running through, it's coated with a film from dryer sheets or fabric softener. Scrub it with warm water, dish soap and an old toothbrush, then let it dry.
The vent run
The duct carrying hot, wet air outdoors is the most common reason a heating dryer won't dry. In many townhouses the dryer sits in an upstairs closet on an interior wall, so the duct has to snake a long way through a ceiling or wall to reach the roof or a side wall. Long runs and extra elbows slow the air even when they're clean. Add lint, and the dryer struggles.
Some checks:
- •Outside: with the dryer running, go find where it exhausts. The flap should swing wide open with a strong, warm stream of air coming out. A weak puff means a restriction somewhere.
- •Roof vents: some townhouse dryers vent through the roof. Those caps can clog with lint or become home to birds, and they aren't easy to reach. Leave rooftop work to someone with the right equipment.
- •Behind the dryer: a foil or vinyl transition hose that's crushed behind the machine throttles the air. Semi-rigid or rigid metal duct is better, and plastic or vinyl duct shouldn't be used at all.
- •Disconnect test: unplug the dryer, pull it out, disconnect the duct at the back, and run a short cycle blowing into the room. If clothes suddenly dry normally, the problem is the duct, not the dryer. Don't leave it that way; it fills the room with lint and moisture, and with a gas dryer it can send exhaust into the room.
Having the full vent run professionally cleaned is sensible if you've never done it, and it's a job for a dryer vent cleaning service rather than an appliance technician.
The washer's spin
A washer that isn't spinning at full speed sends heavier, wetter loads to the dryer. If loads come out of the washer dripping, the dryer isn't the problem.
Load size and the room itself
Overloading slows drying, as does mixing heavy towels with light shirts. A laundry closet with no ventilation also gets hot and humid in summer, and drying time can stretch a little. That's normal; a dryer that suddenly takes twice as long is not.
When there's no heat at all
Electric dryers
An electric dryer runs on a 240-volt circuit. The motor and drum use only half of that, while the heating element needs both. So if one side of the circuit is lost, for example through a breaker that has partly failed, the drum can turn normally with no heat at all. Check the panel: reset both breakers for the dryer by switching them fully off and back on.
If the power is fine, the likely suspects inside the dryer are:
- •Thermal fuse: a one-time safety device that opens if the dryer overheats. On many models a blown thermal fuse stops the heat; on others it stops the whole dryer.
- •Heating element: the coil can break, often after years of overheating from a restricted vent.
- •High-limit thermostat or cycling thermostat.
These are tested with a meter, not by looking.
Gas dryers
Gas dryers use an igniter and a burner. With the dryer running on a heat setting, you can often see the igniter through a small window or opening near the bottom front.
- •Igniter glows, then goes out, and no flame appears: the gas valve coils are a common cause.
- •Igniter never glows: the igniter, a flame sensor or the thermal fuse.
- •Flame lights, then goes out after a short time, and repeats without drying: could be the coils or airflow.
First, confirm the gas valve behind the dryer is fully open and that other gas appliances in the house work.
Why a blown thermal fuse is a warning
A thermal fuse doesn't wear out on its own. It opens because the dryer got too hot, and that's usually because air couldn't get out. Replacing the fuse without clearing the vent means it will blow again, and in the meantime the dryer ran hotter than it should.
Ventless and heat pump dryers
Some condos and apartments use condenser or heat pump dryers that don't vent outdoors. They dry at lower temperatures and take longer by design. These have extra filters, and some have a condenser unit that needs rinsing or a water container to empty. Check the manual. A clogged secondary filter is a frequent cause of slow drying in these machines.
Stop using the dryer if...
- •You smell burning or see scorched fabric.
- •The top or sides of the dryer are too hot to touch.
- •The laundry area gets unusually hot and humid while it runs.
- •A gas dryer produces a rotten-egg smell.
When to call
Book a technician if the dryer produces no heat after you've checked the breakers and the gas supply, if a clean vent and lint screen haven't fixed slow drying, or if the thermal fuse has blown more than once. Tell us whether it's gas or electric and give us the model number.
The technician tests the heating circuit or burner assembly at your home, explains what failed and quotes the repair before any work starts. More detail is on our dryer repair page. If your dryer is stacked above a washer in a closet, the guide to condo and townhouse laundry setups explains what we need in order to reach it, and you can book online once you're ready.
Frequently asked
Can I replace a thermal fuse myself?
The part itself is simple, but the question is why it blew. If you haven't found and fixed the airflow problem, the new fuse will fail too.
How often should a dryer vent be cleaned?
It depends on the length of the run and how much laundry you do. If drying times creep up or the outside flap barely opens, it's time.