My shower has a single handle hot/cold valve.. After some uses it will not turn off. When the valve is pushed in it pushes itself back out. If I turn the water off at the cutoff valve, after a half hour or so it works fine. After some showers it works fine (first thing in the morning). It seems like pressure builds inside the valve and forces it to turn on. What is going on and what is the fix?

Some faucets offer repair parts, like delta, if yours has kits available, repair as needed.

some faucets offer repair parts, like delta, if yours has kits available, repair as needed.

So let me see if I understand you correctly. You are saying that I should fix it - right? Much appreciated.

What's the brand name of your faucet? How old?

The faucet is quite old. I do not see a brand name. The problem seems to be related to heat. If an excessively hot water temp is used (like my daughter) it will not turn off. If more moderate water temp is used it is fine.

Just a guess to start... but does the chrome face plate have 2 screws holding it on? I would remove the handle and then remove the face plate... tell me... is there a copper type clip holding the cartridge in place (on top, pushed down past cartridge)..? If there is a copper clip then it is a moen and you will need a moen replacement cartridge... let us know if this guess is wrong... just something you wrote that sounded like a moen to me.