LG Refrigerator Error dH: What It Means & How to Fix It
Quick answer: dH on an LG refrigerator means the defrost heater didn’t reach its expected temperature during a scheduled defrost cycle — most often because the heater element has failed or a thermal fuse in the defrost circuit has blown.
“Fridge display showed dH and I noticed the freezer getting frosty around the edges. Isken tested the heater and found the thermal fuse had blown, replaced both to be safe, no more ice buildup since.”
Quick Answer
LG fridges run periodic defrost cycles to melt frost off the evaporator coil, monitored by a sensor that confirms the heater actually did its job. dH means that confirmation didn’t happen. Left unaddressed, frost keeps building on the coil, which eventually blocks airflow and causes the whole fridge to run warm — so this code is worth acting on before it becomes a bigger cooling problem.
What Does dH Mean?
The defrost heater itself burning out is the most common cause, followed by a thermal fuse (a safety cutoff that blows if the heater overheats) failing open. Less often, the defrost sensor or the control board’s timer circuit is the actual culprit rather than the heater.
4 Steps to Diagnose dH
Unplug the fridge and locate the freezer back panel.
The defrost heater and thermal fuse are mounted near the evaporator coil behind it.
Look for heavy, uneven frost or ice on the coil once the panel is off.
Confirms the defrost cycle isn’t working, consistent with the dH code.
Test the heater element and thermal fuse with a multimeter.
Both should show continuity — an open reading on either confirms which part has failed.
Replace the failed component.
Heaters and thermal fuses are both straightforward parts, though accessing them means careful panel removal — technician work for most households.
Can You Fix This Yourself?
Removing the back panel to look for uneven frost is a reasonable visual check. Testing the heater and fuse needs a multimeter and comfort working near refrigeration components — doable for confident DIYers, but many people have a technician handle the testing and part replacement in one visit since the panel needs to come off either way.
What Happens When You Call Star Appliance Repair
- Free service call with any completed repair — you’re never charged just to have us look
- Upfront price before any work begins, once the exact part is confirmed
- Most calls booked before noon get same-day service
- Manufacturer-approved parts, backed by our written warranty
Frequently Asked Questions
Will dH ruin my food?
Not immediately, but ice buildup blocking airflow eventually causes the whole fridge to run warm — worth addressing before that happens.
Can I just keep defrosting it manually?
As a short-term workaround, yes — unplugging periodically melts the ice. But it won’t fix the underlying heater or fuse failure.
How much does a defrost heater replacement cost?
It’s a moderate repair — cost depends on which specific part failed, confirmed after testing.
Is this urgent?
Not emergency-urgent, but frost buildup gets progressively worse and harder to keep up with manually the longer it’s left.
*Same-day service is offered whenever possible and depends on technician availability, parts, and your location within the GTA.