Frigidaire · Dishwasher Moderate

UO — Vent fault

The vent assembly used to release steam at the end of the cycle is not operating. The wax motor or the vent door is stuck.

Keep using it?
Yes, with caution
DIY difficulty
Moderate
Verified against
frigidaire.com ↗

How to fix it

  1. Remove the inner door panel to access the vent assembly.
  2. Clean the vent flap and pivot of any grease/film.
  3. Operate the vent flap by hand to confirm it moves freely.
  4. Measure resistance across the wax motor leads (typically a few hundred ohms; open = bad).
  5. Replace the vent assembly if the actuator is open or the door is broken.
  6. Replace the control board if a known-good vent still doesn't actuate.

Why it happens

Typical signs: UO at end of cycle · Cycle completes but with wet dishes due to no venting · Audible buzz from vent motor · Dripping condensation on cabinet face

  • Failed vent wax motor Wax actuator no longer extends to open the vent flap.
  • Vent door stuck closed Food debris or detergent buildup on the flap pivot.
  • Open wiring to the vent assembly Harness pinched in the door.
  • Failed control board vent output Triac or transistor on board no longer drives the actuator.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Frigidaire dishwasher vent assembly / vent fan Common replacement
    Amazon →

Related repair guides

Dishwasher Not Drying Dishes — How to Fix It →

More Frigidaire dishwasher codes

Cd Cd — Door Not Closed / Latched CL CL — Close the door ER ER — Touchpad / Membrane Switch Fault HS HS — Wash Motor Hall Sensor Error i10 i10 — Water Not Detected (Fill) i20 i20 — Drain Blocked

All Frigidaire codes → All dishwasher codes →

Frequently asked questions

What does the UO code mean on a Frigidaire dishwasher?

The vent assembly used to release steam at the end of the cycle is not operating. The wax motor or the vent door is stuck.

What causes the UO code on a Frigidaire dishwasher?

Failed vent wax motor: Wax actuator no longer extends to open the vent flap. Vent door stuck closed: Food debris or detergent buildup on the flap pivot. Open wiring to the vent assembly: Harness pinched in the door.

Is it safe to keep using a Frigidaire dishwasher with a UO error?

Yes, with caution. This is rated a moderate-severity fault.

How do I fix UO on a Frigidaire dishwasher?

Remove the inner door panel to access the vent assembly. Clean the vent flap and pivot of any grease/film. Operate the vent flap by hand to confirm it moves freely.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: frigidaire.com.