I had a new American Standard shower/tub valve installed prior to retiling my tub. After tiling we were installing the trim and the valve leaked. AS sent out a new cartridge and new temperature control unit. We turned the water off and took the cartridge out but the temperature control anti-scald unit resisted coming out and finally a rim broke off. We have been waiting for over a week for the plumber to come back and probably drill out the unit.--empty rent house. I can only guess that it was soldered in. Any other explanation possible? I called AS and they seemed to think this was a homeowner type replacement and to just pull the unit straight out. never used valve. Is American Standard a sub par brand of plumbing? Or was solder dripped onto the unit, melting it and thus making it impossible to remove?