Toilets, Sinks, Showers, Tubs and Disposals - Showerhead issue

Hello - my master bath shower on the second floor has an issue. I seem to be getting very good pressure at the spigot (it's a well pump system), but when I switch to the showerhead, I'm getting less than full pressure (and the spigot is still spewing some water). I'm assuming it's a bad valve or something, in between. Where and how can I fix this? Thanks.

What ever you are "switching" needs repair or replacement.Regardless of type,it is called the diverter and it is not functioning properly.If it's a part you pull up on the spout you probably need a new spout.If it's a part of the faucet itself it needs to be repaired or replaced.

Sorry about my poor terminology. It is when I pull up the tab on the spout to activate the showerhead.

The diverter at the spout has to almost completely block the flow to force the water up to the showerhead. The shower and the spout are all connected to the same pipe basically, so blocking the bottom forces it out the top. If its a special/expensive type spout, you might be able to repair the diverter..but most times the whole spout is just replaced.

Look under the bottom, if you see a slot, there may be some type of setscrew. If no openings on the bottom, than it should just unscrew from the pipe in the wall. Cut any caulk to the wall before trying to remove.

Also with well water, your showerhead may have accumulated some mineral deposits if its not softened. Unscrew the showerhead and soak in warm vinegar for several hours..or you can use CLR (available almost everywhere).