I have a leak in the wall from my shower. The leak is sporadic. I am able to play with the position of the handle (more or less hot water) and I can get it to stop. I was able to narrow it down and determined it only occurs when the hot water is running. I figured it was the cartridge and replaced it. However the leak still occurs.

The shower hardware is MOEN Posi-Temp Pressure Balanced Shower Cartridge model # 1222.

I am hoping not to have to open the wall. What else can I do?

Turn off water and remove cartridge again. Briefly turn on the water and flush out the faucet to remove any debris or mineral deposits that may be trapped in the faucet. Reinstall cartridge.

Thanks for the suggestion. Tried it and unfortunately the leak is still there. I did have a further observation though. It seems the dripping does not start until the water coming out of the shower head becomes hot. So assuming it takes a few seconds to flush the standing water out of the hot water pipe.

I don't understand unless you mean that the tub spout begins to drip when the water out the shower turns hot.

I don't understand unless you mean that the tub spout begins to drip when the water out the shower turns hot.

Sorry, I'll give a little more detail. This is a shower only, no tub. I can hear the dripping on the ceiling of the floor below the bathroom.

I removed the cartridge and flushed both the hot and cold water. I reinstalled the cartridge and turned the water back on. I went downstairs to listen for the leak. I did not hear the dripping for the first 30 to 45 seconds. However after that time the dripping started again.

When this all began I had thought it was the drain leaking. I poured 5 gallons of water down the drain with no leak. Repeated this several times. I then began testing the shower and noticed it only happens when the hot water is running.

Again thanks for your suggestion.

Pull the escutcheon around the shower arm away from the wall.
With a flashlight look in side the wall. If necessary open up the hole that the shower arm comes through so you can see.
I think you will find a leak between the shower arm and the drop ell.

If you do not see obvious signs of water, purchase a 1/2" pipe cap, PVC or iron. Remove the shower head and install the pipe cap on the shower arm. Turn on the water and look for a leak where the shower arm screws into the drop ell.

Pull the escutcheon around the shower arm away from the wall.
With a flashlight look in side the wall. If necessary open up the hole that the shower arm comes through so you can see.
I think you will find a leak between the shower arm and the drop ell.

If you do not see obvious signs of water, purchase a 1/2" pipe cap, PVC or iron. Remove the shower head and install the pipe cap on the shower arm. Turn on the water and look for a leak where the shower arm screws into the drop ell.

Finally found time to try your suggestion. Cap is on. I turned the water on and nothing. No leaking at all. I am stumped.

That indicates that the leak is not from the water supply. With the shower capped off you have exerted the maximum pressure all the pipes and joints of the supply.

Suggest you get one of those flat drain stoppers and block the drain. Fill the shower floor with about 3" of water. Do not use the shower head, fill with bucket from another source. That will eliminate any possibility of the supply being the source. Let the water sit for at least 30 minutes to 1 hour.

If no sign of leak, open drain (I know you have all ready tested the drain).

After that you will have to begin directing the water on the walls. I would be surprised to find a leak there.

PS
Hope you are not confusing the sound of a hot water pipe expanding and popping as it rubs against a structural member for the sound of a drip.