Why Water dispenser of Refrigerator is not functioning?

If your Samsung refrigerator is recently installed, and Water dispenser is not functioning then make sure that it is connected to a water supply and the shutoff valve or saddle valve is turned on. Also confirm water flow through the valve. The ¼" water supply line should deliver at least 9 ounces of water in 5 seconds. If not, the water pressure is low.

Below mentioned are some points you can refer : 

● Is the water line connected and the shut-off valve opened? 
● Has the water supply line tubing been crushed or kinked? 
● Make sure the tubing is free and clear of any obstruction. 
● Is the water tank frozen because the fridge temperature is too low? Try selecting a warmer setting on the Digital display.