FixByModel
F28

Whirlpool F28: Moisture sensor open — resistance too high

F28 means the drum moisture sensor reads open or very high resistance, so auto-dry cycles cannot tell when laundry is dry. The related F29 code is the same sensor reading shorted (too low).

DIY fix

By the FixByModel editorial team · Verified 2026-09 · Researched against manufacturer support & repair references (below)

Most likely causes

  1. Fabric-softener or lint film coating the metal sensor strips
  2. Failed or corroded moisture sensor bar
  3. Broken wire or loose connector in the sensor harness
  4. Poor contact from bent sensor strips
  5. Faulty main control board (less common)
Before you start — unplug the dryer, and on a gas model shut off the gas supply. Let it cool first — the drum, heater and exhaust can be hot. If a step involves the heating element, wiring, or opening the cabinet and you're unsure, stop and call a qualified technician.

Step-by-step fix

1Disconnect powerUnplug the dryer before cleaning or testing the moisture sensor.
2Clean the sensor barsWipe the two metal strips inside the drum (often near the lint screen opening) with rubbing alcohol to remove softener film — this clears many F28 codes.
3Inspect the stripsCheck that the sensor bars are intact, not corroded, and making good contact.
4Check the wiringTrace the sensor harness for breaks or loose connectors and reseat them.
5Test or replaceIf cleaning and wiring checks do not clear it, test and replace the moisture sensor.
6Run an auto-dry cycleConfirm a sensor-dry cycle now completes without the code.

Still showing F28?

If you’ve worked through every step and F28 keeps returning, an internal part likely needs testing and replacement. That’s a job for a qualified appliance technician, who can measure the suspect part against the service-manual spec before replacing it.

Which models this applies to

Whirlpool dryers. Whirlpool numbered-code HE dryers with auto-dry moisture sensing; F28 = sensor open, F29 = sensor shorted.

FAQ

What does Whirlpool F28 mean?

Moisture sensor open — resistance too high. F28 means the drum moisture sensor reads open or very high resistance, so auto-dry cycles cannot tell when laundry is dry. The related F29 code is the same sensor reading shorted (too low).

What causes Whirlpool F28?

The most likely cause is fabric-softener or lint film coating the metal sensor strips. Other causes include Failed or corroded moisture sensor bar; Broken wire or loose connector in the sensor harness; Poor contact from bent sensor strips; Faulty main control board (less common).

Can I fix Whirlpool F28 myself?

Usually yes. Start by working through the steps above, beginning with: unplug the dryer before cleaning or testing the moisture sensor.