I have no water pressure in my new shower. I have a new hot water heater, new shower fixture, new plumbing. Please tell me what the problem is.

Did the problem exist before replacing all this hardware? Are the cutoff valves to the shower fixture turned completely open?

Is the hot and cold OK in the rest of the house, if yes remove the shower head turn on the water and check the water flow if good, clean the shower and remove the restrictor form the head, if the shower head is not your problem, get back to us, good luck.

John