Direct answer
For the LG LF21G6200 counter-depth refrigerator, warm loading, door opening, room heat and recovery are normal; poor seals, airflow and cooling faults are not. First, measure compartment temperatures and door-seal contact.
What this covers
- LG LF21G6200 counter-depth refrigerator (LF21G6200*)
- LG French-door refrigerator; InstaView, Craft Ice, ThinQ and linear/Smart Inverter compressor equipment varies.
- The specific fault this record addresses: runs constantly or cycles too often
What it does not cover
- ×The same symptom on a different LG product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
The unit has a variable-speed compressor and is behaving as designed
What separates it The refrigerator is relatively new, holds correct temperatures, and simply runs quietly and continuously rather than cycling.
How to confirm Check whether temperatures are actually correct. Continuous low-speed running is more efficient than repeated hard starts and is how most current machines work.
- 2
The condenser coils are dirty
What separates it Constant running alongside temperatures that are drifting up, with visibly dusty coils underneath or behind.
How to confirm Reduced heat rejection means the system must run longer to achieve less. This is the most common real cause and is owner-serviceable.
- 3
Door seals are leaking or the door is being held ajar
What separates it Constant running with condensation or frost near the doors.
How to confirm See door-not-closing.
- 4
Recent loading or frequent opening
What separates it Constant running after a large restock or during a period of heavy use, resolving within a day.
How to confirm This is normal recovery behaviour and does not need intervention.
- 5
Ambient temperature is high, or clearance is inadequate
What separates it Constant running in hot weather, or on a unit installed tight against cabinetry with no ventilation gap.
How to confirm Check the manufacturer's stated clearance requirements at the top, back and sides.
- 6
A defrost failure is forcing the system to work through ice
What separates it Constant running with frost accumulating and cooling declining.
How to confirm See frost-ice-buildup.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- Whether temperatures are actually correct — this decides whether constant running is a problem at all.
- The age and type of the unit, since variable-speed compressors run continuously by design.
- Whether the condenser coils are dusty and whether clearance meets the manual's requirement.
- Whether there has been a large restock or unusually heavy use recently.
Measure both compartment temperatures before treating constant running as a fault
ReversibleA modern variable-speed compressor running continuously while holding correct temperatures is working as designed.
Clean the condenser coils
ReversibleThis is the most common genuine cause and is routine owner maintenance.
Confirm the manufacturer's clearance requirements at top, back and sides
ReversibleA unit boxed tightly into cabinetry cannot shed heat properly.
Check the door seals and that nothing holds a door ajar
ReversibleA continuous small air leak forces continuous running.
Allow a day after any large restock before judging
ReversibleRecovery from a big load legitimately takes many hours of continuous running.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- LF21G6200*. LG French-door refrigerator; InstaView, Craft Ice, ThinQ and linear/Smart Inverter compressor equipment varies.
- Type — French door
- A French-door fridge with a bottom freezer. A mainstream LG layout.
- Ice & dispenser
- Automatic ice maker; dispenser on dispenser builds. Ice/water faults trace to the water line, filter and freezer temperature.
- Cooling — Linear Compressor
- Linear Compressor (10-year warranty), quiet variable-speed — a steady hum is normal. Keep interior vents clear for even cooling.
- Symptom boundary
- This record covers LG LF21G6200 counter-depth refrigerator when it runs constantly or cycles too often. A different symptom on the same hardware, or this symptom on a different LG product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Move perishable food and stop for severe heat at the compressor, smoke, or an electrical odour.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. LG publishes this as "[LG refrigerator power] The refrigerator operates continuously. The refrigerator keeps operating without stopping.". Compressor running without cycling off — the exact symptom, including LG's normal-behaviour explanation. What that article does not carry is the model boundary — it is written for a product line, and LF21G6200* is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
My LG LF21G6200 is building up frost inside.+
A little frost near the vents is normal, but heavy frost usually means warm, humid air is getting in — check the door seals for gaps or food holding a door ajar, and do not leave doors open long. Frost specifically on the back wall of the fridge can be a defrost-system issue (heater/sensor), which needs service. Make sure the drawers and vents are not blocking airflow, which causes uneven cold spots and frost.
My new refrigerator never seems to shut off — is that bad?+
Usually not. Most current refrigerators use variable-speed compressors that are designed to run almost continuously at low speed, because that is more efficient than repeatedly starting and stopping. The question that matters is whether the temperatures are correct — if they are, continuous running is the machine working as intended rather than a fault.
It runs constantly and the food isn't as cold as it should be.+
Constant running combined with poor temperatures is a real problem, and dirty condenser coils are the most common cause. The condenser has to shed heat into the room, and when it is matted with dust the system runs longer while achieving less. Cleaning the coils is routine owner maintenance.
Does this answer apply to every LG model?+
No. It is scoped to LF21G6200*. LG French-door refrigerator; InstaView, Craft Ice, ThinQ and linear/Smart Inverter compressor equipment varies.
What should I record before troubleshooting runs constantly or never shuts off?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing runs constantly, never shuts off. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Protect food and stop for severe heat, smoke or electrical odor.
Answer for the exact device and software version shown above.