FixByModel
Er dH

LG Er dH: Defrost cycle did not complete

The defrost system failed to reach its target temperature within the allowed time, so frost is not being cleared from the evaporator coil. A bad heater or defrost sensor is typical.

May need a technician

By the FixByModel editorial team · Verified 2026-09 · Researched against manufacturer support & repair references (below)

Most likely causes

  1. Failed defrost heater element
  2. Faulty defrost thermistor or bimetal sensor
  3. Defrost control relay on the main board not firing
  4. Broken wiring in the defrost circuit
Before you start — unplug the refrigerator before working on it. Mind sharp metal edges, and never open the sealed refrigerant system — compressor, sealed-system and refrigerant work must be left to a qualified technician.

Step-by-step fix

1Reset powerUnplug the refrigerator or trip its breaker, wait about 5 minutes, and restore power to see if the code clears.
2Watch for frostNote heavy frost on the rear freezer wall or weak cooling, which confirms the defrost system is not working.
3Avoid opening the sealed systemDo not attempt refrigerant work; this fault is limited to the defrost heater and sensor circuit.
4Schedule a technicianHave a professional test the defrost heater and sensor with a meter and replace the failed part.

Still showing Er dH?

If you’ve worked through every step and Er dH keeps returning, an internal part likely needs testing and replacement. That’s a job for a qualified appliance technician, who can measure the suspect part against the service-manual spec before replacing it.

Which models this applies to

LG refrigerators. LG refrigerators with automatic (adaptive) defrost and digital fault display

FAQ

What does LG Er dH mean?

Defrost cycle did not complete. The defrost system failed to reach its target temperature within the allowed time, so frost is not being cleared from the evaporator coil. A bad heater or defrost sensor is typical.

What causes LG Er dH?

The most likely cause is failed defrost heater element. Other causes include Faulty defrost thermistor or bimetal sensor; Defrost control relay on the main board not firing; Broken wiring in the defrost circuit.

Can I fix LG Er dH myself?

Some checks are DIY, but this code often points to an internal component, so it may need a qualified technician.