Direct answer: If your LG dehumidifier is running but humidity is not dropping, the usual causes are the set humidity being too high, room conditions overwhelming the unit, restricted airflow from a dirty filter or blocked intake, or the bucket and drain setup keeping the machine from collecting water normally.
Most likely: Start with the basics that fool people all the time: make sure the target humidity is set lower than the room reading, doors and windows are closed, the air filter is clean, and the bucket is fully seated or the drain hose is actually flowing downhill.
A dehumidifier can sound busy and still remove very little moisture. The fastest way through this is to separate a room-load problem from a machine problem, then check the airflow and water collection path before you suspect an internal failure. Reality check: in a very wet basement or a room with outside air leaking in, humidity may drop slowly even when the machine is working. Common wrong move: setting the unit to 60% and expecting the room to feel dry.
Don’t start with: Do not start by ordering a fan, pump, or electronic control part just because the unit runs. Most no-drying complaints turn out to be setup, airflow, icing, or bucket-switch issues.
The fan and compressor seem to run, but the space still smells damp and the humidity number barely moves.
Start here: Start with settings and room conditions first. A high setpoint, open windows, or a wet space that is too large for the unit can make a working machine look weak.
You hear it running, yet the bucket stays mostly empty after hours of operation.
Start here: Check the air filter, intake and discharge grilles, bucket position, float movement, and any drain hose for a clog or uphill run.
Cooling seems weak and you may see ice behind the filter or on the evaporator area.
Start here: Shut the unit off long enough to thaw, then clean the filter and make sure the room is warm enough for normal operation.
The unit says the room is near target, but the space still feels sticky or a separate meter reads much higher.
Start here: Compare the reading with a separate humidity meter placed nearby, away from the discharge air, before assuming the machine has stopped removing moisture.
This is the most common reason. If the setpoint is too high, the room is too large, or outside air keeps getting in, the unit may run a lot without making the room feel much better.
Quick check: Set the target to around 35% to 40% for testing, close doors and windows, and check again after a few hours.
A loaded filter or blocked grille cuts air across the coil, so moisture removal drops hard even though the machine still sounds normal.
Quick check: Remove the filter and inspect it against the light. If it is dusty or matted, wash and dry it before reinstalling.
If the bucket is not seated, the float sticks, or the drain hose is kinked, the unit may stop collecting water properly or cycle oddly without obvious alarms.
Quick check: Reinstall the bucket firmly, move the float by hand to make sure it is free, and confirm the hose slopes downward with no sag full of water.
Ice on the coil chokes moisture removal, and a faulty bucket switch or float switch can make the unit think the bucket is full or out of place.
Quick check: Look for frost behind the filter area and watch whether the bucket-full light flickers or stays on when the bucket is empty and seated.
A lot of dehumidifiers get blamed when the target is set too high or the room is still open to wet outside air. You want to know whether the machine can pull humidity down under fair conditions.
Next move: If humidity starts dropping and the bucket begins collecting water, the machine was likely fighting settings or room conditions, not a failed part. If the room stays damp and water collection is still poor, move to airflow and water-path checks.
What to conclude: This separates a true machine problem from a space that is too wet, too open, or set up wrong for the unit to catch up.
Restricted airflow is one of the most common reasons a dehumidifier runs without pulling much moisture. It is also the easiest fix.
Next move: If airflow feels stronger and water collection improves, the dirty filter was the main problem. If airflow still seems weak or humidity does not improve, check for icing and bucket or drain issues next.
What to conclude: A dirty filter can make the compressor and fan sound normal while the coil does very little useful drying.
Ice and water-path problems often look like the same complaint: the unit runs, but little water shows up and humidity stays high.
Next move: If thawing, reseating the bucket, freeing the float, or correcting the hose gets water moving again, you found the issue. If the bucket is seated, the hose is clear, and the unit still acts like it is full or still removes almost no moisture, the switch or sensor side becomes more likely.
On many dehumidifiers, a small switch tied to the bucket or float tells the machine it is safe to run and collect water. If that signal is wrong, performance can be erratic or the unit may stop short of normal operation.
Next move: If reseating the bucket or freeing the float restores normal operation, keep using the unit and monitor it over the next day. If the bucket signal stays wrong or the unit only works when the bucket is pushed a certain way, the dehumidifier bucket switch or dehumidifier float switch is a supported repair path.
By this point you have ruled out the common setup, airflow, icing, and drain mistakes. What is left is usually a bucket-related switch issue, a persistent humidity-reading problem, or an internal cooling problem that is not a good guess-and-buy repair.
A good result: If the correct bucket-related switch fixes the false full-bucket behavior, the unit should collect water normally and humidity should begin dropping again.
If not: If none of the supported checks change anything, the problem is likely a sensor, control, compressor, or sealed-system issue and is not a smart parts gamble.
What to conclude: This keeps you from sinking money into the wrong part when the real problem is a bad humidity reading or weak refrigeration performance.
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Most of the time it is not a major part failure. The usual causes are a high humidity setting, open-room conditions, a dirty dehumidifier air filter, ice on the coil, or a bucket or drain problem that keeps water from being collected normally.
For a real test, set it lower than the current room reading, usually around 35% to 40%. If you leave it near 55% to 60%, the room may still feel damp even though the unit thinks it is close enough.
Check the easy things first: dirty filter, blocked airflow, bucket not fully seated, stuck float, or a continuous-drain hose that is kinked or pitched uphill. If the unit is icing up, that can also leave you with very little water collection.
Yes. A dirty dehumidifier air filter cuts airflow across the coil, and moisture removal drops fast. The machine can still sound normal, so this gets missed all the time.
Not as a first move. On this symptom, bucket seating, float-switch problems, filter restriction, and drain issues are much more common and much cheaper to confirm. Fan and pump problems are possible, but they are not smart guess-and-buy parts here.
Check it against a separate humidity meter placed a few feet away from the unit and out of the discharge air stream. If the dehumidifier reading is clearly off and the machine cycles like the room is already dry, you are likely dealing with a sensor or control issue rather than a simple maintenance problem.