Quick diagnosis
What this code is telling you
Most likely trigger
defrost heater fault
Recommended replacement
Defrost Heater / Sensor System
Diagnostic path
3 ordered checks
Part fit
Exact model number required
Safety first
Before opening the appliance
Disconnect electrical power before removing panels or handling internal components. Do not bypass safety devices or perform live electrical testing unless you are qualified to do so.
Read the full safety disclaimerRoot cause
Why the control reported this error
F dH or r dH indicates that the refrigerator did not complete the expected defrost operation because defrost heater fault. defrost sensor or fuse fault and control or wiring problem can produce the same code, so verify the fault before replacing components.
Possible causes
Check the most likely causes first
- 1
defrost heater fault
Start here when it matches your symptoms.
- 2
defrost sensor or fuse fault
- 3
control or wiring problem
Diagnostic sequence
Work through these checks in order
Stop when you find the fault. Do not perform a step that requires skills or live testing you are not qualified to do.
- 1
Check 1
Record the code.
- 2
Check 2
Do not chip or pry ice from the evaporator area.
- 3
Check 3
If the code persists, the defrost circuit requires model-specific service diagnosis.
Replacement part reference
Defrost Heater / Sensor System
Exact OEM part number
Model number required
Fitment note
The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.
Verify the appliance model before ordering.
Manufacturers can use different parts under the same error code across model families and production revisions.
Where do I find my model number? →FixCodeDB may earn a commission from qualifying purchases made through affiliate links.
Common questions
Quick answers for this fault
What should I check first for F dH / r dH?
Start with defrost heater fault. If that checks out, continue through the diagnostic sequence above rather than replacing a part based on the code alone.
Does F dH / r dH always mean Defrost Heater / Sensor System is bad?
No. An error code identifies the condition the control detected, not a guaranteed failed part. Confirm the likely causes and wiring first. The exact OEM part number varies by model and production revision. Verify the complete model number before ordering.
When should I stop troubleshooting F dH / r dH myself?
Stop if the next step requires live electrical testing, sealed-system work, gas or combustion service, or any procedure outside your training. Disconnect electrical power before removing panels or handling internal components. Do not bypass safety devices or perform live electrical testing unless you are qualified to do so.
Manufacturer reference
Verify against the official support source
FixCodeDB summarizes the fault in plain language. For model-specific instructions, confirm the guidance with the manufacturer and your appliance manual.
LG Refrigerator Error Code List — LG Support →Was this useful?
Did these checks help with your LG F dH / r dH error?
Keep diagnosing
Related LG guides
LG code 22 is associated on affected refrigerators with a compressor-start or relay-related fault.
LG lists code 33 among refrigerator diagnostic codes; on affected models it indicates a water/ice-system fault requiring model-specific diagnosis.
LG code 67 indicates a door gap or door-related condition on affected refrigerators.
LG lists 88 as a refrigerator diagnostic code that requires model-specific interpretation.
Different problem?
Search another code or symptom
Go back to the main diagnostic search and try the code, symptom, appliance, component, or brand.
Open diagnostic search →