The drum turns, the timer counts down, and at the end the clothes are just as damp and cool as when they went in. A dryer that runs without heating has a working motor and a heat source that isn't firing. The parts involved, and the safe checks, depend on whether your dryer burns natural gas or heats with electricity, so start there.
Gas or electric?
Look behind the dryer.
- Gas dryer: a flexible gas connector runs from a shutoff valve to the back of the machine, and the power cord is a regular three-prong household plug. Around Charlotte, the gas comes from Piedmont Natural Gas.
- Electric dryer: no gas line, and a large, thick cord with a big three- or four-prong plug on a dedicated 240-volt outlet, fed by a double breaker in your panel.
The model label inside the door frame or on the back confirms it. Plenty of homes here have each type, sometimes in the same neighborhood, so don't assume.
Confirm it's really "no heat"
Run the dryer empty on a high-heat setting for about five minutes, then open the door and feel the air and the drum. Warm means there's some heat, and the real problem may be airflow or a cycling fault. Room temperature means no heat at all.
It's worth telling the two apart, because a dryer that heats but takes two or three cycles to dry a load almost always has a venting problem, not a failed heater.
Electric dryers: what to check
Unplug the dryer or switch off its breaker before you pull it out or remove any panel.
The breaker. An electric dryer uses two circuit legs. The motor runs on one; the heating element needs both. If half of the double breaker trips, the drum can turn while the element gets nothing. Switch the dryer's breaker fully off and then back on, even if it looks fine. If it trips again, stop and have the circuit or dryer checked.
The parts behind the heat. If power is good, the usual suspects are:
- Thermal fuse: a one-time safety device that cuts power to the heat (and on some models the whole dryer) when the cabinet gets too hot.
- High-limit thermostat: shuts the heat off when the temperature near the heater climbs too high.
- Heating element: a coil of resistance wire that can break or short against its housing.
- Cycling thermostat or temperature sensor: controls the heat during the cycle; when it fails, heat can be missing or erratic.
These are tested with a multimeter for continuity. If you aren't comfortable with that, it's a short job for a technician.
Gas dryers: what to check
First, make sure gas is reaching the dryer. Is the shutoff valve behind it open (the handle runs in line with the pipe)? Are other gas appliances, such as the range or water heater, working? If your gas service was recently interrupted, the supply needs to be restored before the dryer can heat.
Many gas dryers let you watch the burner through a small window or an opening in the front panel. Start a heated cycle and look:
- The igniter never glows: the igniter, a thermal fuse, a flame sensor, or the control isn't letting the ignition sequence start.
- The igniter glows orange, then goes dark with no flame: gas isn't flowing. Often the valve coils that open the gas valve have weakened.
- A flame lights and then goes out after a short time: the coils, the flame sensor or the gas supply pressure may be at fault.
Don't open gas fittings, loosen the gas valve or disconnect the gas line yourself. If you smell gas, leave the house right away and call your gas utility or 911 from outside. Don't switch lights or appliances on or off on your way out.
Don't skip the vent
On both types, a restricted vent is a frequent reason the heat quits. When moist, hot air can't get out, the dryer overheats. The high-limit thermostat cycles the heat off, and eventually the thermal fuse blows. Replace the fuse without fixing the vent and the new one will blow too.
Lint buildup in a dryer vent is also a fire hazard, which is reason enough to keep it clean. With the dryer running, go outside to the vent hood. You should feel strong, warm airflow, and the flap should open fully. Look for:
- A crushed or kinked transition duct behind the dryer, especially after it was pushed back against the wall.
- Lint packed in the hood or the duct near the wall.
- A bird or wasp nest in the hood.
- Thin plastic or foil duct, which sags and traps lint. Rigid or semi-rigid metal duct is what dryer makers specify.
Many newer two-story homes put the laundry room upstairs, and the vent may run a long way through the attic or exit through the roof. Long runs and roof caps collect lint faster and are hard to inspect yourself. A professional vent cleaning service can clear them.
Never bypass a safety device
It's tempting to jumper across a blown thermal fuse to get the dryer going. Don't. That fuse is the last thing stopping an overheating dryer, and bypassing it removes the protection exactly when something is wrong.
When to call a technician
- The thermal fuse blows again after replacement, even with a clear vent.
- A gas dryer's igniter glows but never lights the gas, or the flame won't stay lit.
- The breaker trips repeatedly.
- The heat comes and goes, or the dryer runs much hotter than usual.
A technician comes to the home, tests the heating and safety circuit, explains what failed and quotes the repair before any work starts. See our dryer repair service for the problems we handle. If the clothes are going into the dryer dripping wet, the washer may not be spinning or draining properly; our washer not draining guide covers that. Not sure we cover your town? Check our service areas.
Frequently asked questions
Why does my dryer heat sometimes and not other times?
An intermittent fault usually points to a part that fails as it warms up. On gas dryers that's often the gas valve coils; on electric dryers it can be a cycling thermostat or a heating element that's starting to break. A partly blocked vent that makes the high-limit thermostat cycle can also cause it.
Can a clogged vent really stop my dryer from heating?
Yes. A blocked vent traps heat in the dryer, which trips the high-limit thermostat and can blow the thermal fuse. On many models a blown fuse means no heat at all until it's replaced, and the vent needs clearing first.
Is a gas dryer harder to repair than an electric one?
Not really, but the parts are different, and any work near the gas valve should be done by a technician. Both types share the drum, motor, belt and venting.
How do I keep this from happening again?
Clean the lint screen before every load, check the vent hood a few times a year, and have long or roof-exit vent runs cleaned professionally. Keep the transition duct behind the dryer short and uncrushed.