Strange faucet behavior

Can't view that page here, but my guess is that loose stem packing is allowing the water pressure / flow to rotate the valve.

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

Do you meant that the handle is actually turning? If that's the case, I have no idea.

If not, maybe the wrong kind of washer, and it gets compressed when the faucet is closed and slowly expands after it's opened?

No, I've not seen the handle actually turn.

Loose washer screw. Possible, I suppose, tho you'd think the water pressure would hold it up?

The washer that's in it has been in service a long time. Used to work fine.

"Law Without Equity Is No Law At All. It Is A Form Of Jungle Rule."

I have experienced this and believe it is due to expansion of the washer and stem from the heat. Some faucets and washers seem to be more prone to this and wear in the threads might be a factor.

Don Young

Change the valves as they are properly worn how old are they , also are they opened or closed when you put them in .

it's the washer swelling up. pretty normal for that type of seal.

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I believe you get the prize. I would call that expansion "rebound" so it might be easier to understand.