LG Refrigerator dH — What It Means & How to Fix It
dH is LG's defrost-heater timeout: the defrost cycle ran past its limit (about an hour) without the evaporator thawing, so the heater or the sensor reading it is at fault.
What this code means
dH appears when the control board has driven a defrost cycle for longer than its maximum and the evaporator still hasn't warmed — LG's board reads the defrost thermistor and, after roughly an hour of no progress, calls it: dH. In plain terms, the defrost heater isn't doing its job, the wiring to it is broken, or a sensor is misreporting the coil so the board keeps defrost alive pointlessly.
LG's documentation places dH as the defrost-timeout (heater) error, distinct from dS, which is the sensor's own reading. A heavily frosted coil behind the freezer's rear panel usually accompanies it. The model number is inside the fresh-food section.
Most likely causes
| Cause | How likely | DIY-fixable? |
|---|---|---|
| Failed defrost heater element | Common | No — technician job |
| Broken or burnt defrost-heater wiring | Occasional | No — technician job |
| Defrost sensor misreading so defrost never completes | Common | No — technician job |
| One-off after a long door-open frost load | Occasional | Yes — manual thaw first |
What you can try yourself
- Unplug the refrigerator and do a manual defrost — this breaks the frost load that can stall an under-powered heater, and it is the only safe DIY step for this code.
- After thawing fully, restart and watch whether the next automatic defrost completes. A clean run means the system may have been overloaded, not failed.
- If frost builds again and dH returns, stop — the heater, its harness, or the sensor pair needs a technician's meter, not another thaw.
- A technician will check heater continuity, the thermal fuse, and the thermistor readings together, because any one of those parks defrost at the timeout.
Seeing the symptom rather than the code? Refrigerator not cooling: checks that apply across brands.
When to call a technician
- dH returns after a complete manual thaw — the heater circuit is genuinely failing.
- A glacier of frost coats the freezer back wall while the fridge warms.
- Water leaks from under the unit as the drain stays iced shut.
Typical professional repair cost: Defrost heater replacement typically runs $150–$300 including labor; a thermistor swap on top adds $120–$220.
Frequently asked questions
Why does LG give up after an hour of defrosting?
The heater is meant to clear a normal frost load in minutes, not an hour. Hitting the timeout tells the board the heater is ineffective or reading wrong — so it stops, reports dH, and waits for a real diagnosis.
Is dH the same as a stuck-off heating element?
Same family of problem: the coil isn't getting warm enough to thaw. The heater can be dead, its wiring broken, or the sensor lying about the temperature — the code alone doesn't choose, which is why the technician meters all three.
My fridge otherwise cools fine — should I rush?
Cooling still works when dH appears, but every week of stalled defrost buries the evaporator deeper in frost and drags the whole unit toward warm-running. Address it before the compressor starts cycling on overload.
Sources checked
Error meanings can vary by model. This guide was checked against the documentation above; use the manual for the model number on your own appliance when it differs.
Related LG codes
- LG Refrigerator Er FF Er FF is LG's freezer evaporator fan fault: the fan that moves cold air through the freezer isn't turning — usually jammed by frost after a defrost, and an unplug-and-thaw reset fixes many cases.
- LG Refrigerator Er rF Er rF is LG's fresh-food evaporator fan fault: the fan serving the refrigerator section isn't turning, so the fridge compartment runs warm even when the freezer stays cold.
- LG Refrigerator dS dS is LG's defrost sensor fault: the sensor on the freezer evaporator reads open or shorted, so the board can't run defrost timing correctly and frost builds over time.
- LG Refrigerator CL E CL E is LG's low-refrigerant warning: the sealed system has lost charge, so cooling gradually weakens. There is no safe DIY step — refrigerant work belongs to a licensed technician.
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