I am having a similar problem as this thread
"Faucet and shower run simultaneously"
https://www.askmehelpdesk.com/plumbing/faucet-shower-run-simultaneously-33198.html

Except that I have a shower with 3 knobs. You turn the middle knob to turn the shower head on.

This shower is at least ten years old and the only thing new is the shower head which is the on a hose with a hook type.

Recently it's gone from a trickle coming out of the faucet to now a lot of water. It's like half faucet and half shower.

Is this something that can be fixed by just replacing the middle knob?

I do not have any plumbing experience.

Thanks in advance

Hey Bubba,

Remove the center diverter stem,(see image, the stems will be the same) and check both the washer and the seat. Run your finger nail around the seat. If it's nicked or rough then it must be replaced. Good luck, Tom