What Er dH Means
Er dH on LG-built Kenmore refrigerators means the defrost heater isn't firing when the control board expects it to — frost can build up on the evaporator coil faster than normal until this is resolved.
Common Causes of Er dH
- Failed defrost heater element
- Defrost thermostat or bi-metal fault preventing the heater from being commanded on
- Control board defrost-timer circuit fault
🔧 One Safe Check You Can Try
This isn't something to open the freezer's rear panel to check yourself — the defrost heater sits behind the evaporator cover and is wired to line voltage, so confirming the fault means a technician's multimeter check on a de-energized unit.
⚠ Why You Shouldn't Go Further Than That
- The defrost heater runs on full line voltage and sits directly against the evaporator coil — testing it live is a genuine shock hazard.
- Reaching the heater means removing the evaporator cover, and a coil damaged during that access can turn a heater repair into a refrigerant leak.
- If ice has already built up heavily on the coil, forcing airflow past it without addressing the heater fault first just refreezes the same ice.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.

