A dryer that tumbles but stays cold is one of the most predictable failures in the house. Heat in a dryer depends on a short chain: power or gas reaching the burner or heating element, a set of safety devices that all agree it's safe to heat, and enough airflow to carry the moisture away. Break any link and the drum turns while the clothes stay damp. The trick is working through that chain in an order that doesn't waste money.
Confirm what you're dealing with
"No heat" and "slow drying" sound alike but often have different causes.
Run the dryer empty on its hottest setting for about five minutes, then open the door and put your hand inside the drum. Warm air means the heat source works, and the problem is most likely airflow or a load that is wetter than it should be. Air that is the same temperature as the room means the heat source isn't firing, and the checks below start with power.
Before anything else, look at the tag on the back or the inside of the door to see if it's electric or gas. Around Tampa, most homes are all-electric and so are most dryers, but gas dryers do exist.
Electric dryers: check the breaker properly
An electric dryer runs on a 240-volt circuit fed through a double breaker. The drum motor and the controls run on one half of that circuit, while the heating element needs both halves. If one half trips, the drum spins and the lights come on, but the element gets nothing.
A tripped breaker doesn't always look tripped. Find the dryer breaker, switch it firmly to off, then back to on. Some fuse boxes still hold two cartridge fuses for the dryer, and one can blow on its own.
After a summer thunderstorm, this is the first thing to check. If the breaker trips again as soon as the heat comes on, stop and call. That points to a short in the element, wiring or terminal block.
The vent run
Most heat complaints that aren't breaker trips come back to the vent. A dryer pushes hot, wet air out through a duct. When that duct is restricted, the drum overheats, and the safety devices cut the heat to protect the machine and the house.
In many Tampa-area homes the laundry sits in the middle of a slab house, with a long vent run through the attic to a roof cap or a distant wall. Long runs with several turns collect lint quickly, and roof caps are easy to forget because nobody sees them. Dryers in an attached garage usually have a short, straight run to an outside wall, which helps, though the cap still needs checking.
Things you can check safely:
- •The lint screen. Hold it under the tap. If water pools on top instead of passing through, dryer-sheet residue has coated the mesh. Scrub it with warm, soapy water and a soft brush.
- •The transition hose behind the dryer. Unplug the dryer before pulling it out. Look for a crushed, kinked or foil-type duct; a semi-rigid or rigid metal duct is the better choice.
- •The outside cap. With the dryer running, go outside and feel for a strong flow of air at the vent. A weak puff means a blockage somewhere along the line. The flap should open freely. Screens don't belong on dryer exhaust caps because they trap lint, and birds or wasps can nest in a cap whose flap doesn't close fully.
Cleaning a long attic or roof run properly takes the right tools and safe access to the roof. Many people hire a vent-cleaning service for that.
Parts that stop the heat
If the vent is clear and the power is good, the cause is usually one of a small group of parts. Which ones depend on the brand and model.
- •Thermal fuse or thermal cutoff. A one-time safety device that opens if the dryer gets too hot. On some models it kills only the heat; on others the dryer won't run at all. A blown fuse is a symptom. Replacing it without fixing the vent is how people end up replacing it again.
- •High-limit thermostat. A resettable switch that opens at a set temperature. If it fails, it can stay open.
- •Cycling thermostat or temperature sensor. It holds the drum temperature where it belongs; a failed one can stop heating or overheat.
- •Heating element. On an electric dryer, the coil can break and stop heating altogether.
- •Control board or timer. Less common, but possible, especially after a power surge.
All of these can be tested with a meter, which is how a technician confirms the fault rather than replacing parts on a guess. Never bypass a thermal fuse or thermostat to get the dryer running again. They're there to stop a lint fire.
Gas dryers
On a gas dryer, the heat comes from an igniter, a flame sensor and a gas valve with a pair of solenoid coils. Some models have a small window near the bottom front where you can see the burner.
- •The igniter glows, then goes dark without a flame. The gas valve coils are a likely cause.
- •The igniter never glows. The igniter, the flame sensor or a thermal fuse may have failed.
- •A flame lights and then goes out after a short time. A sensor or thermostat may be cutting it off, often because of airflow.
Check that the gas shutoff valve behind the dryer is open. Beyond that, gas parts belong to a technician. If you smell gas, don't touch any switches. Leave the house and call the gas company or 911 from outside.
When slow drying isn't a dryer problem
A dryer that heats normally but takes two cycles can be telling you about the washer. If the washer isn't spinning at full speed, the clothes go into the dryer much wetter than they should. Squeeze a towel at the end of the wash. If water runs out, start with the washer; our guide to a washer that won't drain covers that side.
Heavy, mixed loads also dry slowly, and a dryer in a hot, humid garage works harder in August than in January. Our garage laundry guide goes through those conditions.
Safety while you sort it out
Unplug an electric dryer, or turn off the breaker, before pulling it out or opening any panel. If you smell burning or see scorch marks, stop using it until it has been looked at. Clean the lint screen every load, and don't leave a dryer running when no one is home.
Getting it fixed
If the breaker and vent check out and the dryer still won't heat, the next step is testing parts. A technician tests those at your home, tells you which one failed and what the fix costs, and you decide whether to go ahead. There's more on the dryer repair page, or you can book online.
Common questions
My dryer heats, then stops after a few minutes. What's going on?
That is usually a thermostat or sensor cutting the heat because the dryer is running too hot, and a restricted vent is the most likely reason. Check the vent first.
Can a clogged vent cause a fire?
Yes. Lint is flammable and builds up in the dryer and the duct. Keeping the lint screen and vent clear is the most important dryer maintenance you can do.