F3 E3 on a Whirlpool dryer means the moisture sensor has stopped working correctly. The most common cause is a coating of fabric softener or dryer sheet residue on the two sensor bars inside the drum. Clean the bars with rubbing alcohol on a cotton swab first; this fixes the issue at no cost in many cases.
When F3 E3 shows up, your dryer basically goes blind. It can't tell wet from dry, so it either quits way too early or just runs forever. Most of the time when I get called out for this, someone's been using a dryer sheet on every single load for two years straight and never cleaned those sensor bars. Five minutes with a cotton swab usually fixes it. If the sensor's actually fried, you're looking at a $25-40 part.
Phillips #2 screwdriver, Isopropyl alcohol 70% or higher
What Does the F3 E3 Code Mean?
So here's the deal with F3 E3. Those two little metal strips inside your drum are how the dryer knows when your clothes are done. They measure electrical resistance through your wet laundry. When they're coated in dryer sheet wax, or when one of them fails, the dryer throws its hands up and codes out. I fixed three of these in the last two weeks just with a cotton swab and some rubbing alcohol. Seriously, try that first.
Most Likely Causes
Based on aggregated repair data, here is the probability breakdown for this error code:
Fabric softener or dryer sheet coating on sensor bars blocking conductivity40%
Sensor wiring fault or broken harness24%
Control board input circuit for moisture sensor failed22%
Moisture sensor assembly failure14%
Symptoms You May Notice
F3 E3 shows solid on the display and won't clear no matter what you press
Auto-sensing cycles cut off after 10 or 15 minutes and dump wet clothes out like they're done
Dryer runs full 60-70 minutes on every single auto load and never shuts itself off early
Timed dry works totally fine but any automatic or sensor dry cycle acts weird or codes out
Your wool sweaters are coming out shrunk because the sensor thinks everything's already dry and just keeps running heat
Can you reset a Whirlpool dryer to clear the F3 E3 code?
After cleaning the sensor bars or replacing the sensor assembly, unplug the dryer completely for at least 60 seconds. Don't just flip the breaker, actually pull the plug from the wall. Plug it back in, then run a timed dry cycle first, maybe 20 minutes, just to confirm the machine's working normally. If that goes fine, try an auto-sensing cycle with a damp load. The F3 E3 should be gone. If it comes back immediately, you've still got a bad sensor or wiring issue to chase down.
Tools Required for Diagnosis
Phillips #2 screwdriverIsopropyl alcohol 70% or higherCotton swabsFlathead screwdriver for prying panel clipsMultimeter with continuity or resistance modeFine scotch-brite pad for heavy residue buildup
Diagnostic Checklist
Follow these steps in order. We start with the easiest external fixes before opening up the machine.
Replacement Parts
If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.
Part Name
OEM Number
Estimated Price
Moisture Sensor AssemblyWP8566574 · $20–$40
WP8566574
$20 – $40
Frequently Asked Questions
Why do dryer sheets cause F3 E3 on Whirlpool dryers?
Dryer sheets work by releasing a waxy softening coating as they heat up inside the drum. That coating deposits on literally everything in there, including those two sensor bars. Over months of use, the wax builds up into a non-conductive film sitting between the metal surface and your wet clothes. The dryer sends a tiny electrical signal through the bars, expecting wet laundry to complete the circuit and vary the resistance reading. When the wax is blocking the surface, that signal can't get through, and the control board reads it as a sensor fault. Honestly it's kind of ridiculous how simple the fix is.
How often should I clean the moisture sensor bars?
If you use dryer sheets on every load, honestly you should be cleaning those bars every 1 to 2 months. Add it to your calendar right now. If you only use dryer sheets occasionally, every 3 months is fine. If you've switched to wool dryer balls and only use liquid fabric softener in the washer, once or twice a year is enough to knock off any general residue. I've had customers tell me they've owned their dryer 6 or 7 years and never once cleaned the sensor bars. That's how you end up calling me on a Saturday morning.
Can I keep using the dryer while I wait for the new sensor to arrive?
Yes, absolutely. Just switch to timed dry mode. Most Whirlpool dryers let you dial in 40 or 50 minutes of timed heat and tumble, no moisture sensing involved at all. You'll want to check the load yourself rather than relying on the dryer to cut off automatically, but it's totally safe to use it this way until your part shows up. I've had customers run timed dry for a week or two with zero issues. Just don't over-dry your good stuff, check it around the 40-minute mark.
Is F3 E3 the same fault as F3 E2 on Whirlpool dryers?
No, they're different. F3 E3 is specifically the moisture sensor circuit. F3 E2 on some Whirlpool models points to the inlet thermistor, which is a completely different component in a completely different location inside the machine. Don't order parts until you've confirmed exactly which code you have. Sometimes people misread a scrolling display, especially on older control panels. The E digit tells you exactly which sensor circuit is complaining, so write down the full code before you touch anything.
I cleaned the sensor and the code cleared, but it came back a week later. What's going on?
That's almost always heavy dryer sheet use re-coating the bars. If you clean them and the code returns within days, you need to either clean more aggressively with a scotch-brite pad first and then alcohol, or stop using dryer sheets entirely. Wool dryer balls are a solid swap, they soften clothes just fine with zero residue buildup. If the code keeps coming back even after you've ditched the dryer sheets, the sensor assembly has degraded and won't hold a clean surface anymore. At that point just replace it. The part is only $25 to $35 and it's a pretty straightforward swap.
What's the moisture sensor part number for most Whirlpool dryers?
WP3394636 covers a lot of the common Whirlpool models that throw F3 E3. But honestly, always cross-reference your specific model number before ordering, because there are a few variations out there. Pull the model sticker from inside the door jamb, then search that exact model number plus 'moisture sensor' on any appliance parts site. The part usually runs $20 to $40 and ships fast. Don't buy the cheapest no-name version you can find, the OEM or close-to-OEM sensors last a lot longer in my experience.