Dryer Runs but Doesn't Heat: What's Actually Wrong

What's actually happening

A dryer that tumbles without heat has power, a working motor and a working belt — so the fault is in the heating circuit alone. That circuit is deliberately full of safety devices: a heating element or gas valve, a cycling thermostat that switches it on and off, a high-limit thermostat, and a thermal fuse designed to fail permanently if the machine ever overheats. That design matters for diagnosis, because most no-heat dryers are not broken so much as protected: something blocked the airflow, the machine got too hot, and a safety device did exactly its job.

Check these first — they're free

1. Feel the exhaust outside while it runs. Go to the outside vent hood with the dryer running. Strong warm airflow is healthy. Weak or barely-moving air means the duct is restricted — and that is very likely what caused the no-heat condition in the first place.
2. Clean the lint screen and the housing under it. Not just the screen — lint compacts in the slot the screen sits in. A vacuum crevice tool down that housing removes what a screen-clean never touches.
3. Check both halves of the breaker (electric dryers). A dryer breaker is a double. One half can trip while the other holds, giving you a tumbling, heatless dryer. Switch it fully off and back on rather than trusting how it looks.
4. Disconnect the duct and run it briefly. If the dryer heats normally with the duct off, you have proven the venting is the problem and nothing inside the machine has failed. Only do this for a minute or two, and never leave a gas dryer venting indoors.

What causes it, most likely first

Blocked vent duct — the cause behind the cause (most common, you can fix this yourself)

Lint packed in the duct behind the dryer or in the run to the outside wall traps heat inside the machine. The high-limit thermostat or thermal fuse then cuts the heating circuit to prevent a fire. Replace the fuse without clearing the duct and the new one fails too, usually within weeks. This is the reason a technician who does not check your venting has not finished the job — and why a no-heat dryer is worth taking seriously rather than living with.

Blown thermal fuse (most common)

A one-shot safety device on the blower housing or heater box. Once it opens it never resets, and on many models the drum keeps turning while the heat is dead — exactly this symptom. The part itself is inexpensive. The important half of the repair is finding what made it blow, which is nearly always restricted airflow.

Failed heating element (electric) or igniter and gas valve (gas) (common)

On an electric dryer the element is a coil that eventually breaks; on a gas dryer the igniter glows to light the burner and the valve coils open the gas. A gas dryer with a failing igniter often shows an intermittent pattern — heat some cycles, none on others — while an open electric element gives no heat at all, consistently.

Cycling or high-limit thermostat has failed (common)

These switch the heat on and off to hold the drum in range. A failed thermostat leaves the circuit open and the dryer cold. They sit alongside the thermal fuse on the same airflow path, which is why a good technician tests all of them together rather than replacing one and leaving.

Only one leg of the 240V supply is live (electric dryers) (less common)

An electric dryer runs its motor on 120V and its heat on 240V. Lose one leg — a tripped half of a double breaker, a worn outlet, a damaged cord — and the drum turns happily while the element gets nothing. This is worth knowing because the dryer is not faulty at all; the supply is.

When to call a technician

Call when the venting is clear and the heat still does not come — the fuse, thermostats and element are behind panels, and on an electric dryer the heater terminals carry 240V. Gas dryers should not be opened by a homeowner at all: diagnosing an igniter or valve coil means working with the gas train. It is also worth calling if you have replaced a thermal fuse before and it has failed again, because that is the machine telling you the airflow problem was never solved.

How long can it wait? Treat this as urgent, not because of the laundry but because of what causes it. Restricted dryer venting is a leading cause of household appliance fires, and a machine that keeps blowing safety devices is a machine repeatedly reaching temperatures those devices exist to prevent. Stop using it until the airflow has been checked properly.

What it costs

If you fix it yourself: $0–$30 to clear the vent duct and clean the lint housing thoroughly.

Professional repair: A fixed price after diagnosis, agreed before any work starts; the diagnostic fee is applied to the repair when you approve it.

See local dryer repair cost data

Frequently asked questions

Why did my thermal fuse blow again after being replaced?

Because the fuse was the symptom, not the fault. A thermal fuse opens when the machine overheats, and the usual reason is restricted airflow — a lint-packed duct, a crushed transition hose, or a blocked outside hood. Replacing the fuse without clearing the vent means the new one will blow too. Any repair that does not include checking your venting is incomplete.

My clothes are damp but the dryer feels hot. Is that the same problem?

Not quite, though the cause overlaps. Hot but not drying usually means moist air is not leaving — the machine heats, but the humidity stays in the drum. That is nearly always a venting restriction, and it wastes energy on every load until it is fixed.

Can I still use the dryer on the air-fluff setting?

It will tumble without heat, but if the underlying issue is a blocked vent you still have lint packed in a duct where it should not be. Air-fluff avoids the immediate risk without removing it. Get the venting cleared.

How often should dryer venting be cleaned?

Once a year for a typical household, more often with a long duct run, a family that does laundry daily, or if you dry a lot of towels and bedding. If drying times have crept up over the past few months, that is the sign it is due.