I have an American Standard Pressure Balance Bath/Shower Faucet in an upstairs bathroom (Williamsburg model - single lever). Because of water pressure issues (lack thereof when the outside sprinkler system is on), water saver is off.
If I turn the lever on cold, no problem - normal flow of cold water. If I turn the lever - quickly - to hot water, no problem again - normal flow of hot water. However, when the lever is between cold and hot to regulate the temp, the water flow is reduced to a trickle, and a loud hammering noise occurs.
House is fairly new (2001 built) and the bedroom is a spare. My wife and I have tried using the bathroom on several back-to-back days to see if this issue occurred due to lack of use, but the problem is still there.
I am concerned that there may be a problem other than the faucet, which could require ripping up the drywall, etc. Any advice would be appreciated!