Dryer Not Heating: Causes and How to Fix It
Updated · from manufacturer service documentation
If a dryer tumbles normally but produces no heat, the cause is almost always the vent system, the heating element, or a safety thermostat that cut the heating circuit — service documentation from both LG and Samsung independently names the same short list of parts. A restricted vent is the single most common cause across brands and the easiest to check first.
What Causes a Dryer to Stop Heating
| Cause | Likelihood | DIY difficulty | Related part |
|---|---|---|---|
| Restricted/clogged vent system | Most common | Easy — clean lint screen and vent | Vent duct |
| Open (failed) heating element | Common | Moderate — multimeter | Heating element |
| Hi-Limit or thermal cutoff thermostat tripped or open | Common | Moderate — multimeter | Hi-Limit thermostat |
| Regulating thermostat trips easily or is open | Less common | Moderate — multimeter | Regulating thermostat |
| Thermistor reading abnormal (very high or very low resistance) | Less common | Moderate — multimeter | Thermistor |
| Membrane switch open (some models) | Less common | Moderate — multimeter | Membrane switch |
How to Fix a Dryer That Won't Heat, Step by Step
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Check the lint screen and full vent run first
LG's FLOW SENSE™ system and Samsung's own troubleshooting both flag vent restriction as the leading cause of heating complaints — clean the lint screen and inspect the vent duct for clogs, crushed sections, or excessive length before checking any part.
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Confirm the dryer runs normally otherwise
These heating causes assume the motor runs and the drum tumbles; if the dryer won't start or run at all, that's an unrelated fault (belt, motor, door switch).
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Test the heating element
On LG's electric platform, the service diagnostic checks element winding resistance (18–22 Ω per heater bank, 36–44 Ω combined) and resistance from the element terminal to the housing (should read under 1 Ω — a higher reading means a ground/short issue). Samsung's documentation lists an open heating element as a direct cause of "will not heat" with the motor still running.
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Check the Hi-Limit and thermal cutoff thermostats
Both LG and Samsung documentation point to a tripped or open Hi-Limit/thermal-cutoff thermostat as a common heating-circuit interrupter — these are safety devices that cut power to the heater if temperatures run too high, often as a downstream symptom of restricted airflow.
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Check the regulating thermostat and thermistor
Per Samsung's documentation, a regulating thermostat that trips easily, or a thermistor reading far outside normal resistance (too high or too low), both stop proper heating even with a good element.
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Check the membrane switch (if your model has one)
This is another documented point of failure in Samsung's "will not heat" diagnostic, alongside the thermostats.
Where This Comes From
Cross-referenced from LG's DLEX3570/DLEX4270/DLGX7188 service manuals (electric platform heater test, resistance specs) and Samsung's DV42H5000-DV45H6300 service manual (will-not-heat diagnostic table). Both brands independently converge on vent restriction, heating element failure, and tripped safety thermostats as the core causes — which is why this is written as a brand-agnostic symptom page rather than duplicated per brand.
Brand-specific pages: LG d80 and d90 (duct-blockage codes), Samsung dryer not heating.
Frequently Asked Questions
Is a dryer not heating always a vent problem?
It's the single most common cause across brands, but not the only one — a failed heating element, a tripped thermostat, or a bad thermistor can all produce the same symptom even with a completely clear vent.
Why does my dryer tumble fine but produce no heat?
The motor and heating circuits are separate systems. A failure anywhere in the heating element, its safety thermostats, the thermistor, or vent airflow stops heat without affecting the drum or motor at all.
Can I test the heating element myself?
On LG's electric platform, yes — with the dryer unplugged, a multimeter check of the element windings (18–22 Ω per bank) and the element-to-housing resistance (under 1 Ω) confirms whether the element itself has failed.
Should I replace parts myself, or call a technician?
Check the vent and lint screen yourself first — that resolves most cases. Testing the heating element, thermostats, or thermistor needs a multimeter and some disassembly; if you're not comfortable with that, it's a reasonable point to call a technician.
Based on the LG service documentation for the DLEX3570, DLEX4270, and DLGX7188 dryer series, and the Samsung service documentation for the DV42H5000-DV45H6300 dryer series. Last updated: .