When a water faucet fails to work correctly, it is more about identifying the source of the problem rather than actually having to fix or replace it. There are a few different reasons why water will not run from a faucet when turned on.
Tighten the faucet assembly screw located under the decorative cover located on top of the controller or faucet. Pry the decorative cover off with a flathead screwdriver and tighten the screw underneath with a Phillips screwdriver.
Check your water pump. Make sure your water pump is on and functioning. If the water pump is on but is not working, check its fuse box for a blown fuse. Turn the water pump off, unplug it and replace any bad fuses.
Turn other faucets on to see if they are working properly. If not, look at the main water shut-off valve to see if it is the "open" or "on" position.
Inspect the aerator on the end of the faucet. Unscrew the aerator from the faucet tip and look for debris that may be obstructing the water flow.
Unfasten the water pipe using an adjustable wrench or plumber wrench. Shine a flashlight into the pipe to illuminate it and check for obstructions.