Before you begin. This procedure is general reference information, not professional advice. Equipment varies by manufacturer, model, and year. Always follow the documentation supplied with your equipment — where it differs from this page, follow the manufacturer. Verify that you have the tools, the working conditions, and the ability to do this task safely. If anything is unclear, if the equipment is damaged, or if the task exceeds your experience, stop and use a qualified professional. You are responsible for your own safety and for the outcome. This site accepts no liability for any loss, damage, or injury arising from the use of this information.
Specifications marked unverified could not be traced to a manufacturer source. Do not rely on them — obtain the value from your equipment documentation.
Summary
Most clothes dryers with an automatic or "auto dry" setting use two small metal bars inside the drum to sense when a load is dry. Fabric softener and dryer sheets leave a thin film on these bars over time, and the film stops them from sensing moisture correctly. The dryer then behaves as if the load is already dry and the cycle ends early, so the clothes come out damp. This is one of the most common reasons a dryer "stops before the clothes are dry" or an "auto dry" setting seems to stop working, and the fix is usually a simple wipe.
This page shows where manufacturers say to look for the sensor bars and how to clean them, using each maker's own instructions for its own dryers. Samsung, GE Appliances, Whirlpool and LG do not all agree on the exact spot or the cleaning agent, so this page names each position rather than picking one. If a clean set of bars does not fix a damp load, the fault is more likely the heating system, the airflow, or the sensor itself, and this page does not diagnose those.
Safety
CLEAN THE LINT FILTER BEFORE OR AFTER EACH LOAD.
Lint can block the air flow. Blocked air flow can start a fire in the dryer.
Necessary equipment
| Item | Note |
|---|---|
| Vacuum cleaner with a hose optional | Whirlpool names a vacuum for the lint trap and the sensor bars on its own dryers. |
| Soft cloth | Samsung and GE Appliances each name a soft or a damp cloth for their own sensor bars. |
| Clean towel optional | Samsung names a towel to dry the bars after you clean them. |
| Mild soap material | Samsung names a mild soap for its own sensor bars. |
Prepare the dryer
Estimated under a minute
DISCONNECT THE DRYER FROM THE ELECTRICAL SUPPLY BEFORE YOU CLEAN THE SENSOR BARS.
Contact with the electrical supply can give you a shock.
- Disconnect the dryer from the electrical supply.<1mReport a problem with step 1, Prepare the dryer
- Open the dryer door.<1mReport a problem with step 2, Prepare the dryer
Find the sensor bars
Estimated 1 min
Source: Ventless Condenser Dryer - How to Maintain Optimum Performance · tier 1 · accessed 2026-08-04
- Find two metal bars inside the dryer opening, near the lint filter.<1mReport a problem with step 1, Find the sensor bars
- GE Appliances names the inside of the dryer opening for its ventless condenser dryers.
- Samsung names the inside of the dryer drum for its own dryers.
- The documentation for your model gives the exact position.
- Vacuum loose lint from around the two bars.<1mReport a problem with step 2, Find the sensor bars
- Whirlpool names a vacuum for this area on its own dryers.
Clean the sensor bars
Estimated 1 min
No tier-1 source was found for this value. Take it from the documentation supplied with your equipment.
- Wipe each bar with a soft cloth.<1mReport a problem with step 1, Clean the sensor bars
- Samsung names a soft cloth with mild soap for its own dryers.
- GE Appliances names a damp cloth for its ventless condenser dryers.
- Use the agent named in the documentation for your model.
- Dry each bar with a clean towel or another cloth.<1mReport a problem with step 2, Clean the sensor bars
- Samsung names a towel or another cloth for this step on its own dryers.
- If a film remains, wipe the bar again.<1mReport a problem with step 3, Clean the sensor bars
- Samsung says that a film from fabric softener can coat the bars.
- The load stays wet when the film coats a bar.
Finish the job
Estimated under a minute
- Connect the dryer to the electrical supply.<1mReport a problem with step 1, Finish the job
- Close the dryer door.<1mReport a problem with step 2, Finish the job
Terminology
This page uses one term for each item and holds it throughout, as ASD-STE100 requires. Equipment sellers and other guides use the names below for the same parts.
- moisture sensor bars
- Also called: sensor bars, moisture sensor, humidity sensor, dryness sensor, auto dry sensor, moisture sensor strips, sensor strips, dryer sensor bars
- lint filter
- Also called: lint screen, lint trap, fluff filter, dryer filter
When to use a professional
Stop if the load stays damp after you clean the sensor bars. Run a full program before you decide. This procedure does not repair the sensor.
Speak to the manufacturer or a qualified technician about the sensor or the control board. Do not open the control panel or the wiring behind it. Speak to a qualified technician for repair inside the dryer.
Common questions
Why does my dryer stop before the clothes are dry?
The most common cause is a dirty moisture sensor. Most dryers with an automatic or "sensor dry" cycle use two metal bars inside the drum to detect moisture, and Samsung says a residue from dryer sheets can build up on these bars and stop them from detecting moisture, so the dryer ends the cycle while the load is still damp. LG describes the same effect for what it calls the humidity sensor. Cleaning the bars is usually enough to fix it.
My auto dry setting is not working. Is this the fix?
It is the first thing to check. An auto dry or sensor dry setting relies on the moisture sensor bars, and a residue film is the most common reason Samsung and LG give for a setting that seems to stop working or misjudge the load. Clean the bars first, then test the setting again before you assume it is broken.
Where are the moisture sensor bars in my dryer?
The exact spot is different for each maker. GE Appliances names the inside of the dryer opening for its own ventless condenser dryers, Samsung names the inside of the dryer drum for its own dryers, and Whirlpool describes the same area as the outside of the lint trap. Look near the lint filter opening first, and check the documentation for your own model if you cannot find them.
What should I clean the sensor bars with?
Manufacturers do not agree, so this page does not pick one method. Samsung says its own sensor bars can be cleaned with a soft cloth and mild soap, then dried with a towel. GE Appliances says to simply wipe its own ventless condenser dryer sensor bars with a damp cloth, and names no soap. Whirlpool instructs a vacuum for the same area on its own dryers and names no wipe or cleaning agent for it. Use the method your own manufacturer names.
How often should I clean the moisture sensor?
GE Appliances names once a month for its own ventless condenser dryers. Samsung, Whirlpool and LG do not give a specific interval; each says to clean the bars regularly, or when a residue builds up. If loads are drying unevenly, or the auto-dry setting is ending cycles too soon, clean the bars regardless of when you last did it.
Is "humidity sensor", "moisture sensor" and "sensor bars" the same part?
Yes. LG calls its own version the humidity sensor, and Samsung, GE Appliances and Whirlpool each call theirs the moisture sensor or the sensor bars. All four names describe the same job: metal contacts that sense how wet a load is during an automatic drying cycle.
I cleaned the sensor bars and the dryer still stops too early. What now?
Run one full program first, since a single wipe does not always remove every trace of residue. If the load is still damp after that, the cause is more likely the heating system, the airflow, or a fault in the sensor itself. Speak to the manufacturer or a qualified technician; this page does not cover diagnosis beyond a clean set of bars.
Related procedures
- How to clean the lint filter in a tumble dryer
- How to clean a clogged dryer vent and lint duct
- What dryer vent hose is safe, and how long can it be?
- How to test a dryer thermal fuse with a multimeter
- How to clean the drain filter on a front loading washing machine
- How to clean the rubber door seal on a front loading washing machine
- How to run the tub-clean cycle on a washing machine and what to put in it
- How to level a washing machine that walks, shakes or bangs on the spin cycle
Sources
Every specification on this page is traced to one of these sources. Tier 1 is a manufacturer document, a published standard, or a government safety authority. See Standards for the full tiering rule.
- Tier 1How to clean your Samsung dryer
- Tier 1Overheated Clothes Dryers Can Cause Fires (CPSC Publication 5022)
- Tier 1Ventless Condenser Dryer - How to Maintain Optimum Performance
- Tier 1How to Clean a Dryer in 9 Steps
- Tier 1LG Dryer - How to Clean the Humidity Sensor
Revision history
Current version 1 · updated 2026-08-04 · next review due 2027-08-04
- v1 · 2026-08-04First draft. Sourced to Samsung and CPSC Publication 5022, both already registered, and to GE Appliances (ventless condenser dryers), Whirlpool and LG manufacturer support documentation for the sensor bars' location, symptom and cleaning method. The cleaning agent publishes as consult-the-manufacturer with a conflict_note: Samsung names a soft cloth with mild soap, GE Appliances names a damp cloth only for its own ventless condenser dryers, and Whirlpool names a vacuum and no wipe. Two of five sources are already registered; the three new manufacturer entries are staged in data/sources-additions-clean-a-dryer-moisture-sensor.json for merge into data/sources.json by an authorized actor.
Corrections to this page are listed in the public corrections log. Reports that are credible and not yet verified are listed in the public errata register, and an open one renders above the step it concerns.
Comments and corrections
Found an error? A correction with a manufacturer source is applied and logged publicly. You can also write to corrections@fixchecklist.com.
Every step above carries its own report control, which tags the report with that step so a correction reaches the right place. For anything about the procedure as a whole — the order of the sections, a step that is missing, something that did not match your equipment — use this: report something about this whole procedure.