When water does not dispense, it may be related to operational issues that can be easily resolved. The recommended temperature for LG refrigerators is -4oF(20oC), if your unit's temperature is lower, this may cause frozen water lines which will prevent water from dispensing.

Humming sound from dispenser.

Press the dispenser button or lever. Listen to hear if the dispenser hums or sounds like its trying to dispense water.

New installations.

For newly installed units, air may be trapped in the water line between the home water supply and the unit, which will prevent water from dispensing. Try holding down the dispenser lever until it dispenses water. Be sure to discard the first 1-2 gallons of water before consuming.

Check water flow to dispenser.

Check if water is getting to the dispenser. To do so, remove the filter and hold it over the sink with the tip facing down.

Since there is water is in the filter, this indicates that the water supply is on but something is restricting the flow. With the water filter removed, try to dispense water. If the unit requires a bypass, it must be installed.

If water dispenses from the unit, this indicates that either the filter needs to be replaced  or the water pressure is too low.

Water filter that should be changed every 6 months. If not replace regularly as directed, foreign particles may build up on the filter, which will reduce the water pressure and flow rate. If the filter was recently replaced, verify that it is installed correctly.