1- is this an older building with Galvanized piping?
2-Are you using well water?
3- If it is city water, is the city doing any repairs/maintainence to this system?
4-How often do you actually flush out your hot water heater as per instructions supplied by the heater manufacturer?
5-Was the NEW shower installed by a Licensed Master Plumber or someone dabbling in this profession?
6- Who ever installed the new piping did they flush out the lines properly to make sure no acid type flux is remaining?
7- Was the drain installed to a proper diameter (2″)?
8- Was this drain properly pitched AND snaked out to the main prior to being put into service?
9- Was this shower properly vented?
10- If you let water down another fixture do you get a slight back up in the shower base?
Good luck
SylvanLMP.. Expert witness serving serveral Manhattan law firms.
[Edited by SylvanLMP on 02 April 2000]