1. Clogged vent — the #1 cause across every brand
What it is: Lint accumulation in the vent run (especially long runs to a roof or rim-joist termination) chokes airflow. The high-limit thermostat trips on overheat, cuts the element, and the dryer keeps tumbling with no heat. Symptom: clothes take 2+ cycles to dry, dryer top feels very hot, clothes smell scorched. We find this on roughly 4 in 10 'not heating' calls — and it's also the leading cause of dryer fires.
Fix: Disconnect, brush the full vent run from inside and outside, verify ≥1,500 ft/min airflow at the hood, test high-limit and cycling thermostats for reset. No parts needed if thermostats reset cleanly.
Typical all-in: $185–$265 all-in (includes vent cleaning + safety test)
2. Blown thermal fuse (electric & gas)
What it is: A one-shot safety fuse on the blower housing pops when vent restriction sends temperatures over spec. Symptom: dryer tumbles but no heat at all, ever. Whirlpool / Kenmore / Maytag 27-inch platforms are the most-frequent service. We always replace the fuse AND fix the vent — replacing only the fuse means a repeat call within weeks.
Fix: Replace OEM thermal fuse, clean the vent run, verify high-limit and cycling thermostat operation in the same visit. Test full hot cycle before closing.
Typical all-in: $165–$245 all-in
3. Tripped half of the 240V breaker (electric dryers only)
What it is: Electric dryers pull 240V — one half (120V) runs the motor and controls, the other half powers the heating element. If only one half trips, the dryer runs but doesn't heat. Symptom: dryer turns on, tumbles, lights work — but no heat ever, even on a brand-new install or after a storm.
Fix: Reset both breakers fully (off then on). If it trips again under load, the dryer outlet or the breaker itself has failed — call an electrician, not a dryer tech. We diagnose voltage at the outlet on the first visit.
Typical all-in: DIY · $0 if it's a breaker reset
4. Failed heating element (electric)
What it is: The coiled nichrome heating element inside the heater box opens up after 6–12 years. Symptom: zero heat, often after a long stretch of slow drying. Whirlpool 27-inch, Samsung DV, and LG DLE platforms are the most-common service. Element resistance tests open on a multimeter — clean diagnosis.
Fix: Replace OEM heating element, inspect heater box for arc damage, replace cycling thermostat and high-limit at the same time (they're $20 parts and they've absorbed heat-cycles for years).
Typical all-in: $265–$385 all-in
5. Failed igniter or flame sensor (gas)
What it is: Gas dryers use a glow-bar igniter to light the burner. After 5–10 years it cracks or loses output. Symptom: motor runs, you hear no click, no flame, no heat. The flame sensor (radiant sensor) sits beside the burner and tells the gas valve when to open — a failed sensor blocks ignition even with a healthy igniter.
Fix: Test igniter resistance (should read 50–400Ω), test flame sensor for continuity, replace OEM igniter and/or flame sensor as found. Cycle 3 burner ignitions before closing.
Typical all-in: $245–$345 all-in
6. Failed high-limit thermostat or cycling thermostat
What it is: Both thermostats mount on the blower housing / heater box. The high-limit trips on overheat (and won't reset), the cycling thermostat cycles the element on and off to hold temperature. Symptom: heats briefly then quits, or never heats after a known-good vent. Common at year 8+ across all platforms.
Fix: Test both thermostats for continuity (cold) and reset behavior, replace OEM as found. Always paired with a vent inspection because thermostat failures are a downstream symptom of vent restriction.
Typical all-in: $185–$285 all-in
7. Failed control board (rare — last suspect)
What it is: If element / igniter / fuse / thermostats all test good, the main control board has failed to send the heat-call signal. We find this on under 5% of 'not heating' calls — usually after a power surge or on Samsung / LG units past year 7 with moisture-corroded board pins.
Fix: Verify heat-call voltage at the board harness in service mode, replace OEM control board if no signal. Samsung DV / LG DLE / Whirlpool main boards are stocked.
Typical all-in: $385–$525 all-in
