How To Fix a Dryer Moisture Sensor

Updated: Nov. 29, 2023

When it's set to Auto Dry, does your dryer keep running for hours? Clean your dryer's moisture sensor and your problem may be solved.

Next Project
Time

A few minutes

Complexity

Beginner

Cost

Free

Introduction

When using the Auto/Sensor Dry feature, a moisture sensor determines when the clothes are dry and shuts off the unit. Sometimes the sensor gets dirty and stops working, which wastes time and energy. Fortunately, this is a dryer repair you can DIY fix. It will take you less than five minutes to get your moisture sensor working again.

Tools Required

  • Wire brush

Materials Required

  • Alcohol wipes
  • Fine sandpaper

Why Your Moisture Sensor Stops Working

Over time, the two metal strips inside your dryer that make up the main component of your moisture sensor may stop functioning. This is especially true if you use dryer sheets.

Dryer sheets coat everything inside your dryer, including the metal strips, with a waxy film. That prevents the strips from sensing moisture from your wet clothing. When that happens, the sensors can’t tell when the clothes are dry.

Cleaning the metal strips is quick and easy with alcohol wipes, a wire brush or fine sandpaper. Note: If you use dryer sheets, clean the moisture sensor once a month.

dryer moisture sensorFamily Handyman

Project step-by-step (5)

Step 1

Locate your moisture sensor

  • Look inside the dryer drum for two metal strips, about four inches long and side-by-side.
  • It could be just behind the plastic housing that holds your dryer lint filter.
  • Or it could be on the back wall of the dryer drum.

Locate your moisture sensorFamily Handyman

Locate your moisture sensorFamily Handyman

Step 2

Clean your moisture sensor

  • Wipe the two metal strips with your alcohol wipe three or four times until the metal is shiny. Or…
  • Rub the two metal strips with your small wire brush until the metal is shiny. Or…
  • Lightly rub the two metal strips using your fine, 400-grit or above sandpaper.

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Step 3

Test your clean moisture sensor

  • Set your dryer for Auto Dry.
  • Soak a cotton shirt in water, then ring it out so it’s moist but not sopping wet.
  • Put the moist shirt in your dryer and start it, using the Auto Dry setting.
  • Come back in 30 minutes to confirm the shirt is dry and the dryer turned itself off. If your dryer is still running, repeat the cleaning and testing process.
Step 4

FAQs

Do all dryers have moisture sensors?
Many modern clothes dryers and all Energy Star certified dryers feature moisture sensors, whether gas, electric, or heat pump dryer models.

What are the symptoms of a malfunctioning dryer moisture sensor?
The cause of dryer moisture sensor issues can be difficult to diagnose, but the usual symptoms include the dryer not heating up or the auto cycle finishing without the clothes being completely dried.

Can I run my dryer without the moisture sensor?
In general, yes, but unless your dryer has manual, time-dry settings and you use them, you are unlikely to completely dry your clothes.

Step 5

When to call a pro

Just finding the moisture sensor can be challenging depending on the model of the dryer. If you are having problems finding the moisture sensor or are unfamiliar with or uncomfortable servicing your clothes dryer, the best course of action may be to contact an appliance repair technician.