A refrigerator water dispenser that is not dispensing any water or that is dispensing water slowly, might have an issue with a number of parts. However, the first and easiest thing you should check is the water filter.
Over time, refrigerator water filters gather impurities from the water that they filter, which can lead to a buildup of impurities inside the filter itself. Changing your water filter could possibly fix the problem of a slow water filter dispenser or one that does not work at all.
Another part that might be causing a broken water dispenser is frozen tubing. Locate the tubing running through the refrigerator door and check to see if it is restricted by ice by removing the tubing and blowing air through it. You can also store your food and other perishables in a cooler and try defrosting the tubing by bumping up the temperature inside the freezer and refrigerator or unplugging the refrigerator completely for 24 hours.
Check the micro switch (also called a dispenser switch or an actuator switch) to see if it is broken and needs to be replaced. The micro switch is usually located behind the water dispenser facade and is activated by the dispenser actuator (the lever you push your glass against to get water). If this switch is broken, it will not send power to the water valve and you will not receive water.
The water inlet valve supplies water to the dispenser when activated. Low house-hold water pressure might cause the valve not to work properly. Make sure your household water pressure is 20 pounds/square inch (PSI).The water inlet valve can also become defective and will need to be replaced.