Kenmore ER dH Error Code — What It Means
The ER dH code (also shown as F dH or r dH on LG-built Kenmore models) signals a defrosting failure. The refrigerator started a defrost cycle, but the defrost sensor did not detect the expected temperature rise within the allowed time window. In the service manual for these units, the specific condition is that the sensor did not reach 46°F within one hour after defrost started. This fault means frost and ice are not clearing from the evaporator coil, which blocks airflow and causes poor cooling in both compartments.
In practical terms, the code tells you that either the defrost heater is not warming the coil, the sensor or thermal fuse has failed and cannot report temperature correctly, or ice and blockages are so severe that even a working heater cannot melt them in time. LG’s official guidance lists ice accumulation, blocked drainage, heater disconnection, sensor or fuse disconnection, and main control board failure as the root causes.
Common Causes
- Heavy frost or ice buildup on the evaporator coil Repeated incomplete defrost cycles leave a thick ice blanket that the heater cannot clear in the allotted time, triggering the code.
- Failed defrost heater If the heater element is open or not receiving power, the coil never warms and frost stays in place.
- Defrost sensor, thermistor, or thermal fuse failure An open thermal fuse or drifted thermistor will report incorrect temperature data, causing the board to flag a defrost timeout even if the heater is working.
- Blocked drain hole or drain path Meltwater refreezes in the drain trough and builds ice that insulates the coil and prevents proper defrost.
- Main control board fault The PCB may fail to energize the heater or may misread sensor signals, stopping defrost prematurely or reporting a false error.
Step-by-Step Fix
- Unplug the refrigerator and remove all items from the freezer compartment so you can safely access the evaporator cover.
- Remove the rear evaporator panel inside the freezer and inspect the coil for heavy frost or a solid ice blanket that confirms a defrost problem.
- Let the unit thaw completely if ice is severe, either by leaving it unplugged with towels in place or using a hair dryer on low heat aimed at the coil (never touch the coil with the dryer).
- Test the defrost heater for continuity using a multimeter, and verify that the control board supplies approximately 115 VAC to the heater terminals during a forced defrost test.
- Check the defrost sensor and thermal fuse assembly for continuity, replacing the assembly if the fuse is open or the sensor reads far outside the expected resistance range for freezer temperature.
- Clear the drain hole and drain trough of any ice or debris so meltwater can flow to the drain pan and not refreeze on the coil.
- Reassemble the evaporator cover, restore power, and monitor the freezer for at least 24 hours to confirm that temperatures stabilize and frost does not rapidly return.
Parts Often Needed
| Part | Notes |
|---|---|
| Defrost sensor and thermal fuse assembly | Amazon | Most common failure point. Match the part number to your exact Kenmore or LG model. |
| Defrost heater | Amazon | Replace if continuity test fails or if the element shows visible breaks or burn marks. |
| Main control board (PCB) | Amazon | Required only if testing confirms the board is not energizing the heater or is misreading sensor input. |
When to Call a Pro
Call a professional if you are uncomfortable working with 115 VAC circuits during defrost testing, if you cannot safely remove heavy ice without damaging the evaporator fins, or if you have replaced both the sensor assembly and heater but the code returns. A technician has the service manual resistance tables and can run board-level diagnostics to isolate control faults that are difficult to confirm with basic tools. If your refrigerator is still under warranty, contact Kenmore or LG support before opening any panels so you do not void coverage.