Can't remove water filter for LG refridgerator

After you shut the water off, unscrew the canister, remove old filter and check it against new filter. (They should be the same) check fo arrows (if there are any point in upward position) insert and screw canister back on, fasten securely, turn water back on.

Check the dispense lever, could be sticking

Well this never happens with me but surely you might get some unusual result.
Chlorinated Solvents Exporters

Unplug the machine and unscrew the phillips head screw on the back grill of the machine, that is just above the plug. There are depressions on the sides of the back grill that has a plastic tang that hold the back grill to the machine. Press the back grill inwards to allow the tangs to clear the sidee and the back grill should now be easily removed. Remove the two thumb screws on the top corners to remove the filter. Once the filter is removed, then you can remove the purification plate and remove the two screws that hold the RCI cell. The RCI cell and filter can be cleaned by vacumming out the dust and dirt.

The purification plate can be cleaned with a old toothbrush and a water and amonia solution. Scrub the metal grid with the toothbrush. Do both sides and then rinse with water, allow it to dry completely before reinstalling the plate. After every part is cleaned reassemble the purifier, and plug it in. Then press the reset reminder button on the front of the keypad to clear the "perform cleaning" message. This message will appear again after the purifier runs for 30 days to remind you to clean the purifier. Hope this helps you.

The Classic XL-15 should have 2 individual indicator lights. The 'red' light is the ionizer indicator, and the 'green' light is the ozone level indicator. Both lights should be illuminated, if the unit is operating properly. The red light should be pulsing, and the green light should be dimly lit, and brightened as the output knob is turned up - indicating a higher ozone production. If the green light is not lit, you likely won't smell the ozone. The first thing you should try, is cleaning the filter and glass ozone plate. Unplug the unit and remove the rear air filter. Clean the filter with clean water and allow to COMPLETELY air dry. Removed the glass plate by depressing the lever behind the glass plate, and gently pulling it out. Clean the glass with a half water, half ammonia (or distilled white vinegar, if ammonia not available) and an old toothbrush to clean between the mesh. Dry plate with a hair dryer and re-place plate into unit. Replace dried air filter, making sure the little tab on the bottom is secured into the interlock. Power the unit on and you should see the indicator lights and smell the fresh ozone!

if the metal screen is removable, run under warm water and gently brush with damp rag
if no removable, unplug unit, wipe clean with damp rag

electronic circuit needs replacement

When mine gets stuck I stick the handle of a fork or spoon into the hole where the water comes out and use that to unscrew it. Works like a charm every time.

If it says "Clean Cell Now" and it is a new machine, it is broken. I have six, yes six, of this model. They are all new and you shouldn't have to clean the filter/cells for a few months.

The way to clean is:

1. Unplug
2. remove the white cover
3. remove the prefilter. Good time to clean the prefilter by removing the 2 retention clips and gently swing the prefilter outward. Clean or groom it with a vacuum. Use the upholstery brush. wash the prefilter in warm, soapy water. No Chlorine! Rinse clean with regular water. Wipe with a paper towel and let dry completely. It is okay to gently use a hair blower to speed up the drying process.
4. Onto the Cell.
5. The cell can be washed one of two ways. Either in a hot tub of water or in a dishwasher.
6. Wear gloves to protect your hands. Never touch the fins or wires. It will ruin them and cut you up. Use the two handles.
7. Use hot water and dish detergent.
8. No chlorine and no abrasives.
9. Soak for 10 minutes, then dip a couple of times to remove stuck dust/dirt/schmutz.
10. Rinse with clean water.
11. Allow to dry
12. Allow to dry
13. Allow to dry
14. Okay to use a hair dryer to speed up process.
15. Reinstall
16. Power up
17. Press and hold CHECK button for 3 secs to reset.

Thanks.

Since you weren't very specific where it leaks or when it started (like after a filter change) it could be tough to troubleshoot this leak.

If it is leaking at the faucet connection try tightening up where it screws onto the faucet. Depending on your strength (or lack of) you may need to use pliers to get a tight connection. Don't go crazy tight or it will crack the plastic fitting. If it still leaks remove the unit from the faucet and check the rubber washer inside where it screws onto the faucet. Make sure it's still there and is centered inside the cup and seated properly. Then reattach the unit to the faucet and tighten it well.

If it's leaking from the main body try removing the filter and reinstalling it making sure you have seated the filter properly and screwed on the cover correctly, and all the way. When it is tight the water outlet will be exactly at the bottom of the unit. Sometimes it's tricky getting it tight enough especially with wet hands.

Finally, if the leak is coming from the filter on/off selector this could be tough to fix. I would try firmly pushing and pulling the selector knob in and out several times while in both the on and off positions. This may re-seat the leaking seal. I wouldn't be too hopeful about this fix though. You may need to replace the unit if this part is leaking.