A rarely used shower faucet was working OK. I turned it off (cleaning the shower floor) and when I turned it on again, no water came out. I tried full hot, full cold and cycled the valve numerous times to no avail.

Just checked and faucet is "Stanadyne". Made by Moen? It was installed 20 years ago and is in a back bathroom and hasn't been used 10 times since new.

Anyone?