Too hard to turn by hand

Move it off and on a few times it may loose and close completely, good luck.

John

Loosen the packing nut just a little, spray some WD40 on the nut joint and valve shaft and try again. If you are going to replace the HW heater, install a 3/4 ball valve.

Just noticed it is a PVC valve. What type of valve is it?

Just the question I was going to ask Ma064.
Do you have a wheel or a lever for a handle? Back to you. Tom