Shower won't turn on

There may be a number of causes for your shower to not turn on. You can attempt the following to troubleshoot the problem:

Verify that the shower's water supply is turned on. This could be found in your home's main water supply valve or behind the shower itself.
Verify that the shower handle is all the way open.
Inspect the showerhead for obstructions. If required, take out and clean the showerhead.
Check to see if the valve that regulates the water flow to the shower is worn out or damaged.
Make that the shower hose is not kinked or obstructed.
If none of these remedies work, the shower or plumbing system may be the source of the issue. In that situation, it might be preferable to contact a licenced plumber to identify and resolve the problem.