Dryer Not Heating — The Complete Diagnostic Guide (Every Cause, In Order)

Before You Call Anyone — Two Things to Check First

The Circuit Breaker (Electric Dryers Only)

Electric dryers run on a 240-volt circuit using two separate 120-volt legs wired through a double breaker. When only one leg trips, the machine receives half voltage — enough to run the motor and drum but not enough to power the heating element. The drum rotates, the timer counts down, but there is no heat. Go to the electrical panel, find the double-width dryer breaker, push it firmly all the way to OFF and then back to ON. Both legs reset together. Test the dryer again before any further diagnosis.

The Gas Supply (Gas Dryers Only)

Confirm the gas shutoff valve behind the dryer is fully open — the handle should be parallel to the pipe, not perpendicular to it. Confirm the gas supply to the house has not been interrupted. A gas dryer with no gas supply runs the drum and motor normally but produces no heat because the burner never ignites.

Cause 1 — Blown Thermal Fuse (Most Common)

The thermal fuse is a one-time safety device that permanently cuts power to the heating circuit when the dryer exceeds a critical temperature. Once blown, it cannot reset — the circuit stays open until the fuse is physically replaced.

Symptom: No heat. Drum runs normally. On some Whirlpool and Maytag models, a blown thermal fuse kills power to the entire machine — display goes dark, nothing responds.

Test: Unplug the dryer. Locate the thermal fuse — on electric dryers typically on the heating element housing; on gas dryers typically on the burner assembly. Test with a multimeter on continuity. A functioning fuse shows continuity. A blown fuse shows none.

Cause 2 — Failed Heating Element (Electric Dryers Only)

The heating element is a coil of high-resistance wire that generates heat when current passes through it. When the coil develops a break, the circuit opens and no heat is generated. A partial failure — some coil sections broken, others intact — produces reduced heat rather than complete no-heat.

Symptom: No heat or reduced heat. Drum runs normally.

Test: Unplug. Access the heating element housing. Test for continuity — intact element shows continuity, failed element shows none. Also visually inspect the coil for visible breaks, dark spots, or areas where the coil has sagged and contacted itself or the housing. On well-water properties, check for mineral scale accumulation on the element surface — scale acts as insulation and causes the element to overheat at contact points.

Cause 3 — Failed Gas Igniter (Gas Dryers Only)

The igniter heats to glowing orange to provide the initial ignition source for the gas burner. The gas valve coils require the igniter to reach operating temperature before they energise — so a failed igniter means the gas valve never opens and the burner never lights.

Symptom: No heat. Drum runs normally. You can observe the igniter through the burner access panel during operation — a functioning igniter glows orange. A failed igniter shows no glow.

Test: Unplug. Test the igniter for continuity — a functioning igniter shows resistance (50–400 ohms depending on material type), not open circuit. A cracked igniter shows open circuit.

Cause 4 — Failed Gas Valve Coils (Gas Dryers Only)

The gas valve is opened by electromagnetic coils. When a coil fails, the valve does not open even when the igniter reaches full temperature — gas never reaches the burner.

Symptom: The igniter glows correctly but no flame appears. The igniter then cuts power and the cycle repeats — glow, no flame, cut, glow again. This cycling-without-flame pattern is the classic gas valve coil failure signature.

Test: Unplug. Test each coil for continuity and correct resistance range (varies by manufacturer). A failed coil shows open circuit or out-of-range resistance.

Cause 5 — Failed Cycling Thermostat

The cycling thermostat regulates drum temperature by switching the heating element or gas valve on and off. When it fails open, it permanently breaks the heating circuit.

Symptom: No heat. Drum runs normally. Indistinguishable from a thermal fuse failure by symptom alone.

Test: Unplug. Locate the cycling thermostat — typically on the exhaust duct or blower housing. Test for continuity at room temperature. A functioning cycling thermostat shows continuity at room temperature. A failed-open thermostat shows none.

Cause 6 — Failed High-Limit Thermostat

The high-limit thermostat is a secondary safety device that cuts the heating circuit above the cycling thermostat’s range. When it fails open, it permanently breaks the heating circuit before the thermal fuse is reached.

Symptom: No heat. Indistinguishable from cycling thermostat or thermal fuse failure by symptom alone.

Test: Same continuity test as the cycling thermostat. Located near the heating element or burner assembly.

Cause 7 — Failed Radiant or Flame Sensor (Gas Dryers)

Some gas dryers include a radiant sensor that monitors whether the burner flame has been established. A failed sensor may prevent the gas valve from staying open after ignition, producing the same cycling-without-sustained-flame pattern as gas valve coil failure. Component testing distinguishes between the two.

Cause 8 — Failed Control Board

On modern electronic dryers — particularly Samsung and LG — a failed main control board can prevent the heating circuit from activating even when all heating components test correctly. This is the last diagnosis made after all upstream components have been ruled out.

The Diagnostic Sequence — In Order

Electric dryers:

1. Reset both legs of the circuit breaker properly
2. Test thermal fuse for continuity
3. Test heating element for continuity, inspect visually
4. Test cycling thermostat for continuity at room temperature
5. Test high-limit thermostat for continuity
6. If all above test correctly, assess control board

Gas dryers:

1. Confirm gas supply is on, pressure adequate, type matches machine configuration
2. Test thermal fuse for continuity
3. Observe igniter during operation for glow — test for continuity if no glow
4. If igniter glows but no flame, test gas valve coils and radiant sensor
5. Test cycling and high-limit thermostats
6. If all above test correctly, assess control board

Related: Dryer Not Heating in Pensacola · What Is a Thermal Fuse? · What Causes a Dryer to Overheat? · Gas vs Electric Dryer Repair