Toilets, Sinks, Showers, Tubs and Disposals - Low flow and noise in tub faucet

I have a single handle faucet in the tub. When it is rotated to either the hot or cold side and turned on, there is plenty of water and no noise. However, when it is in the middle between the 2 extremes, the flow decreases, begins to spurt and the pipes in the wall actually start banging.

What causes this and how can it be fixed? The faucet brand is American Standard.

Thanks

Most single handle faucets have a cartridge. Something may have broken in it. I have included American Standards website and toll free phone number. Perhaps you can find your model on the website and find a part number. If not, call them and get the info you need. Good luck.

American Standard 1-800-442-1902
http://www.americanstandard-us.com/

I called American Standard and they informed me that it sounded like the pressure balancing cartridge. There are 2 cartridges in the faucet. The pressure balancing one and the on/off one. They told me that although the directions state to remove the cartridges before soldering that sometimes the instructions aren't followed and some internal parts melt or deform.

I installed the new pressure balancing cartridge and while it seemed to help, after the water runs for approx. 15 seconds, the sputtering begins (not as bad) and the pipes begin rattling in the wall.

Could the on/off cartridge also be a problem? Again, everthing works correctly at full hot and at full cold - just not when both are chosen.

The price of replacing the other cartridge may be worth getting rid of the problem. Good luck.

I got the cartridge yesterday and just finished installing it. The cartridge and the pressure balance unit (both now replaced) are American Standard and were purchased from American Standard directly so they are OEM parts. This unit does not have stops beside the valve body.

The pipes still rattle badly when the faucet is opened all the way with both hot and cold selected evenly (Handle is perpendicular to the floor).
I checked the valve body to see if there was any "play" while I had everything dismantled thinking that the pipes may not be supported correctly but there isn't any "play" at the valve body. I can't get to the rest of the pipes. When they rattle, you can feel the vanity / sink shake which is about 5 ft. away on the opposite wall than the tub.

This bathroom also has a separate shower and that faucet works fine. No problems with the sink either.

What's left to check / fix?

Thanks

Any other ideas? I really need to get this resolved.

Thanks