F31 Serious Hard — consider a tech

LG Dishwasher F31 — Heat-dry fan motor failure

LG Dishwasher · Error code F31

What F31 Means

On Dynamic Heat Dry models the dry-fan motor is not running when commanded. The wash cycle finishes but dishes will not dry properly.

Symptoms

  • F31 shown at end of cycle
  • Dishes wet after Dry phase
  • No fan noise during the drying portion
  • Cycle otherwise completes normally

Common Causes

1
Failed dry fan motor

Burned winding or seized bearing in the dry blower.

2
Loose fan motor connector

Harness backed out at the door or main PCB.

3
Obstructed fan housing

Debris in the fan blade preventing rotation.

4
Main PCB driver fault

Triac for fan output failed.

How to Fix It

  1. Note model number and order a Dynamic Heat Dry fan motor that matches it.
  2. Power off at breaker, remove the inner door panel screws, and locate the fan motor at the top of the door.
  3. Inspect blade for foreign material; rotate by hand — should spin freely.
  4. Test motor windings and connector continuity.
  5. Replace fan motor if open or seized.
  6. If a known-good motor still does not spin, replace the main PCB.
  7. Reassemble and run a Heavy cycle; verify fan audible during Dry phase.

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.

Common replacement LG dishwasher heat-dry fan motor View on Amazon→

More LG Dishwasher Codes

2H 2H — Delay-start indicator (2 hours remaining) AE AE — Leak Detected (Aqua Error) bE bE — Bubble / oversuds error CE CE — Motor / communication error CL CL — Child lock / control lock active CR CR — Test / calibration mode

All LG codes → All dishwasher codes →

Verified against manufacturer documentation: lg.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.