Whirlpool · Dryer
Whirlpool Dryer F28 Error Code
Moisture sensor circuit failure
What this error means
F28 means the moisture sensor bars inside the drum front are not returning valid readings. Auto-dry cycles that rely on conductivity across the bars cannot determine when clothes are dry.
How F28 is detected
When F28 appears on a Whirlpool dryer, the control board has confirmed that water did not leave the machine within the programmed drain window. On Whirlpool WED6600MW, Whirlpool WED5620HW, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most F28 calls are resolved without parts: unplug the dryer and wipe the two metal sensor bars inside the drum with rubbing alcohol. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If F28 returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Fabric softener residue insulating the sensor strips
- Loose moisture sensor harness connector inside the drum bulkhead
- Broken sensor bar wiring from drum rotation wear
- Failed sensor bar assembly reading open
Step-by-step fixes
- 1Unplug the dryer and wipe the two metal sensor bars inside the drum with rubbing alcohol
- 2Remove accumulated dryer-sheet waxy coating using a non-abrasive pad
- 3Check the harness behind the front bulkhead where the sensor wires exit
- 4Run a sensor dry cycle after cleaning—F28 at start means replace the sensor bars
When to call a technician
Sensor bar replacement requires front bulkhead access—schedule service if cleaning and harness checks do not clear F28.
Affected models
- Whirlpool WED6600MW
- Whirlpool WED5620HW
- Whirlpool WGD5620HW
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use dryers to prevent F28 from lint and food debris buildup.
- Record when F28 appears in the cycle and whether it clears after a 60-second power reset on your Whirlpool dryer—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for F28; Whirlpool uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting F28; reversed plugs on pumps and valves cause immediate repeat faults.