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E939LG Dishwasher

LG Dishwasher Error E939 – Meaning, Causes & How to Fix

The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit.

Medium Severity
Low
Medium
High
Critical

Expert Verified

Reviewed by a Certified Electrical Engineer & Licensed Technician

Official Meaning

The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit.

Real-World Causes

  • 1Loose wiring harness
  • 2Clogged inlet filter screens
  • 3Faulty inlet valve solenoid
  • 4Water supply faucets are not fully open
  • 5Low water pressure in the plumbing system

Symptoms

Look for these signs to confirm error E939 on your LG Dishwasher:

  • Error displayed at the start of a cycle
  • Appliance stops mid-cycle
  • Unusual clicking sounds as relays activate
  • Machine pauses and displays the error

DIY Fix (Safe)

  1. 1Verify household water and power supply conditions
  2. 2Inspect hoses and filters for blockages
  3. 3Restart appliance after disconnecting power for 5 minutes
  4. 4Clean filters and sensors if accessible
  5. 5Run diagnostic mode if available

Professional Action Required

  1. 1Test valves, sensors, and motors with a multimeter
  2. 2Inspect wiring harness and connectors
  3. 3Replace defective pumps, motors, sensors, or valves
  4. 4Inspect control board relays
  5. 5Replace electronic control board if failure is confirmed

Additional Context

Load Type
Any load type
Drain Related
Depends on cycle stage
Sensor Issues
Sensors may give incorrect readings if hoses are blocked

Frequently Asked Questions

What does LG Dishwasher error E939 mean?
The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit.
What causes LG Dishwasher E939 error?
Common causes include: Loose wiring harness, Clogged inlet filter screens, Faulty inlet valve solenoid.
How do you fix LG Dishwasher error E939?
Start with these DIY steps: Verify household water and power supply conditions. Inspect hoses and filters for blockages. If the error persists, professional service may be needed.

Related Error Codes

Other LG Dishwasher Errors

E876The appliance control system detected a condition indicating temperature sensor fault – thermistor readings are outside expected range
E552The appliance control system detected a condition indicating water supply error – the appliance is not receiving adequate water supply
E186The appliance control system detected a condition indicating temperature sensor fault – thermistor readings are outside expected range
E736The appliance control system detected a condition indicating temperature sensor fault – thermistor readings are outside expected range
E189The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit
E268The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit
E505The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit
E124The appliance control system detected a condition indicating overflow protection triggered – water level exceeded safe limit

About the Author

Technical Review Team

Reviewed by certified technicians with 10+ years of LG repair experience. Every error code is verified against manufacturer service manuals and real-world repair data.