FB
Whirlpool Dishwasher
Severity: ModerateWhat Does This Error Mean?
The FB error means your Whirlpool dishwasher's vent wax motor has a problem. The vent system opens during the drying cycle to release steam and moisture. If the wax motor fails, the vent doesn't open and dishes don't dry properly. This is a moderate error — the machine still washes, but the drying cycle is affected.
Affected Models
- WDT750SAHZ
- WDT970SAHZ
- WDTA50SAHZ
- WDF520PADM
- Whirlpool dishwashers with active vent drying
Common Causes
- Wax motor actuator in the vent assembly has failed and can no longer open the vent flap
- Vent flap stuck closed due to food residue or mineral buildup around the flap
- Wiring harness connection to the vent wax motor is loose or corroded
- Control board not sending the activation signal to the vent motor at the correct time
- Vent assembly cracked or physically damaged preventing proper operation
How to Fix It
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Cancel the cycle and open the dishwasher door.
Inspect the vent opening, which is usually on the inside of the door panel at the top. Look for any visible food debris, white mineral deposits, or physical damage to the vent area.
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Clean around the vent flap opening with a damp cloth.
Remove any buildup around the vent flap that could be preventing it from opening. Use a toothpick carefully to clear mineral deposits from around the flap edges.
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Try to manually open and close the vent flap if accessible.
Some vent flaps can be gently pushed open by hand. If it moves freely when pushed, the flap itself isn't stuck — the wax motor that opens it has likely failed.
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Unplug the dishwasher for 10 minutes to reset the control board.
A power reset can clear an FB error caused by a temporary wax motor communication glitch. Run a drying-only cycle after the reset if your model supports it.
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If FB persists after cleaning and resetting, the wax motor assembly needs replacing.
The vent wax motor is located in the door assembly and replacement requires opening the inner door panel. This is a moderately involved repair — consider calling a technician.
When to Call a Professional
If cleaning the vent doesn't clear FB, the wax motor needs replacing. The vent assembly is typically on the inner door panel of the dishwasher. A licensed appliance technician can replace the vent assembly efficiently. Expect repair costs of $80–$200 for a vent wax motor or vent assembly replacement.
Frequently Asked Questions
What does the dishwasher vent do?
The vent releases hot steam from inside the tub during the drying phase. As steam escapes, cooler air replaces it and helps the dishes dry faster. This is called active vented drying — different from the fan-assisted drying on some models. If the vent stays closed, steam condenses back onto your dishes leaving them wet and spotty.
Will dishes still get clean with the FB error?
Yes — the FB error only affects drying, not washing. The wash and rinse cycles run normally even when the vent motor is faulty. Your dishes will be clean but noticeably wetter at the end of the cycle. Opening the door slightly after the cycle helps them air dry in the meantime.
Is the FB vent error the same as the F10 dispenser error?
No — they both involve wax motor components, but in different parts of the machine. F10 is the detergent dispenser wax motor — controls when detergent releases during the wash. FB is the vent wax motor — controls when the vent opens during drying. Both are wax actuator failures, but they are different parts in different locations.