LG Dishwasher Error Code SE1 — Steam Generator High Temperature Error (TrueSteam)
What this means
The SE1 error code appears on LG dishwashers equipped with TrueSteam technology. It indicates the steam generator has reached an abnormally high temperature, suggesting the steam heater is overheating, the steam water level sensor is malfunctioning, or the NTC (negative temperature coefficient) thermistor that monitors the steam generator temperature has failed. The steam generator produces high-temperature steam to sanitize dishes and improve cleaning performance. When SE1 triggers, the steam function is disabled to prevent damage. The dishwasher may still run wash cycles without steam. To view steam generator error codes, press and hold the SPRAY and HALF LOAD buttons simultaneously — SE0 means no error.
Alternate codes: SE 1
Step-by-step fix
4 stepsPower-reset the dishwasher
Turn off the dishwasher's circuit breaker for 1 minute, then restore power. Run a normal cycle to see if the SE1 code returns. A temporary sensor glitch can cause a one-time SE1 error.
After restoring power, check the steam error status by pressing SPRAY + HALF LOAD simultaneously. SE0 means the error has cleared.
Check the water supply to the steam generator
The steam generator needs water to produce steam. Ensure the main water supply to the dishwasher is fully open and that water pressure is adequate. If the steam generator runs dry, it can overheat and trigger SE1.
Low water pressure or a partially clogged inlet valve can starve the steam generator of water.
Inspect the steam generator for scale buildup
In hard water areas, mineral scale can accumulate inside the steam generator, insulating the heating element and causing it to overheat. If accessible, inspect the steam generator for visible white scale deposits.
Running the dishwasher with a citric acid-based dishwasher cleaner monthly can help prevent scale buildup in the steam generator.
Test the NTC thermistor
Unplug the dishwasher and locate the steam generator NTC thermistor. Disconnect it and test with a multimeter. At room temperature, it should read approximately 10,000–12,000 ohms. A wildly different reading or OL indicates failure.
If the thermistor reads correctly, the steam heater relay on the control board may be stuck closed, causing continuous heating.
When to call a professional
If the SE1 code returns after a power reset, a technician should inspect the steam generator assembly, NTC thermistor, water level sensor, and the control board's steam heater relay. Steam generator components are not commonly user-replaceable.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
Learn more about our sourcesParts you may need
Steam Generator Assembly
Part #AJH73993401 · $80–$150
If the steam generator has internal scale damage or a burned heater
NTC Thermistor (Steam)
Part #6322FR2046C · $10–$20
If the thermistor reads out of spec on multimeter testing
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