LG Refrigerator Runs Constantly? Causes & Fix

What's normal for an LG#

Traditional refrigerators cycle: the compressor runs 30 to 40 minutes, then stops for 20 to 30. LG's Linear Compressor does not work that way — it runs quasi-continuously at a variable speed, easing off during light-load periods like a cool night and briefly pausing during a defrost every 8 to 12 hours. You will hear a soft, rhythmic clicking that rises and falls with the piston speed. If your LG holds the set temperature and the sound level varies, constant running is normal and nothing is wrong.

When it really is a fault#

It is worth investigating only when temperatures are climbing, or when the compressor is stuck at full speed and never eases. Smart Diagnosis can confirm this directly (below), but the practical sign is a box that runs hard and warm at once, or a noise that never softens even overnight.

Causes at a glance#

Working through the causes#

Dirty condenser coils (35%). The condenser rejects the heat pulled from the box, and coils caked with dust, pet hair, or grease cannot shed it. The Linear Compressor answers by running at maximum speed continuously to keep up, which is the most common reason for genuine high-speed constant running. Clean the coils and the compressor can drop back to its normal, easy cadence.

Leaking door seal (25%). A gasket that has hardened or lost its magnetic pull lets warm room air seep in nonstop, so the compressor never catches up. Run the dollar-bill test: close the door on a bill and pull — easy slip-out means a weak seal. Clean or replace the gasket so it grips all the way around.

Defrost fault or frost buildup (20%). If the defrost system fails, frost blankets the evaporator and chokes airflow, so cooling drops and the compressor runs on trying to compensate. Look for heavy frost on the evaporator coil behind the freezer panel; that points to the defrost heater, sensor, or control.

Warm setting or hot location (15%). Sometimes the fridge is simply asked to do too much — set too cold, sitting next to an oven or in direct sun, or crammed against the wall with no airflow. Confirm the setting is reasonable and give the unit clearance and distance from heat before suspecting a part.

Low refrigerant (10%). A slow refrigerant leak leaves the compressor running hard while cooling gradually fades. This is sealed-system, specialist work — leak location, repair, and recharge by a licensed technician — never a DIY fix.

Check with Smart Diagnosis#

LG's ThinQ Smart Diagnosis reads the compressor directly: open the app, start Smart Diagnosis, hold the phone near the left door hinge, and press the Refrigerator Temp button for about 3 seconds. The readout includes compressor speed, run-time percentage, and any fault codes. A compressor reported at 100% duty cycle continuously confirms a genuine fault rather than normal variable running.

What it costs you#

A genuine constant-running fault burns roughly 30 to 50% more electricity than normal, and on a French-door model rated around 700 kWh a year that adds up on Sacramento power rates. More important than the bill, the extra heat and full-speed running stress the compressor and shorten its life, so it is worth fixing promptly.

A quick self-check before you call#

You can separate "normal" from "faulty" in a few minutes without tools. First, put a thermometer inside for an hour — if the fridge holds around the high 30s and the freezer near zero, the constant running is just the Linear Compressor doing its efficient thing. Second, listen at night: normal running softens during light-load hours, while a faulty unit stays loud and steady. Third, feel the condenser area and the sides of the cabinet — unusually hot surfaces and a fan that never eases suggest the compressor is pinned at full speed. Fourth, pull the lower rear panel and look at the coils; if they are furred with dust, you have likely found the cause before spending anything. Only if temperatures are actually rising, or the box runs hot and hard around the clock, does it warrant a service call.

Preventing a repeat#

• Clean the condenser coils every 6 months — every 3 with pets or in dusty fire season.
• Check the door gaskets seasonally with the dollar-bill test.
• Keep the fridge away from ovens, dishwashers, and direct sun, with about 4 inches of rear and 2 inches of side clearance.
• Avoid installing it where ambient temperatures stay above about 90°F.

LG compressor never shutting off and the box is warming? Our technicians diagnose coils, seals, and defrost same-day across Sacramento and the Bay Area. Book your repair.