The shower head in my master shower just suddenly stopped spraying. Now the water just comes out, but not in a spray. I know that's not very clear, but I don't know how to describe it. Its pretty old, but has always worked great. How can I tell if its the shower head, or a valve, which is what my husband thinks
Most shower heads are easy to unscrew. If you can do so, take it off, examine the head and see how much flow you have with no head in place. Don't unscrew the supply tube inside the wall! Unscrew the shower head from the supply tube.
When you screw it back on, usually you don't need pipe dope or Teflon tape on the threads because the usual head has a rubber seal that the end of the supply tube presses on. Over time the seal may be hardened and lose the ability to seal.
Does this head have a knob to change the spray pattern?
Schmutz in showerhead holes.
This happened to me. Schmutz had come down the pipe (it was blue!) and occluded holes in the shower head. They rinsed out ok. We had to do that periodically until whatever was giving rise to these blue particles was used up.
If you have particulate matter from old pipes or hard water it could do the same thing.