If your showerhead is constantly dripping water or spraying incorrectly during use, there is a good chance that the problem is a worn out or damaged washer inside the showerhead itself. Fortunately replacing a shower washer is a simple job that you can do without calling a plumber. A bad washer wastes water, increases utility bills and makes the shower itself perform poorly. In just a few minutes, you can have it working perfectly.
Turn off the water supply to the shower so that you can work on the showerhead without water pouring out of the pipes. Turning the water off at the stop-valve will generally take care of this.
Open the taps and turn on the shower to let all the water drain out or the shower after the water supply is turned off. This will make it easier to remove the hardware without getting wet when it comes loose.
Detach the showerhead from the shower arm by hand if possible. Most showerheads unscrew counter-clockwise and can be loosened by hand, but you might need a pipe wrench to take off some heads if they are stuck due to rust or limescale. With particularly hard to remove showerheads, you may need to use two pipe wrenches and put one on the head and one on the shower arm to break it loose. Be careful not to damage or crack the showerhead, especially if it is plastic.
Remove all the build-up on the showerhead and shower by soaking the parts in vinegar. Simply submerge the head in a bowl of white vinegar for an hour or two and tie a vinegar soaked cloth around the end of the shower arm to remove limescale and clean it thoroughly.
Locate the washer on the inside of the showerhead and remove it. It is typically located in the area where the head connects to the shower arm. The washer is a small, black ring made of rubber. You will likely see some wear or slight damage that was causing the water to leak around it. Replace the washer by sliding a new one of the exact same size into place.
Wrap Teflon or silicon plumber's tape clockwise around the threads of the shower arm to help seal the gap between the arm and showerhead. Screw the showerhead back into place and make sure it is snug. You may need to give it a slight twist with a pipe wrench to ensure it is tight enough to prevent water leakage. Turn the water back on and the problem should be fixed.