Customer called in because of shower valve to perform replacement. Customer requested we attempt to perform replacement of cartridge first. Had maintenance shut water down to whole building. Drained down system. Performed replacement of first cartridge with no issue. Called customer and had a conversation about next steps. Customer requested while building is shut down for us to perform replacement of remaining cartridges except for one shower that is no longer in use. Performed replacement of remaining two cartridges. Had maintenance return water to system. Checked for leaks. No leaks found. Note: set screw for handle on valve that was exposed was not installed. Could not locate set screw. Had a conversation with receptionist and she said that they would contact person who removed tile and see if they have set screw. Note: left 3 cartridges with customer per customer request. Thank you for choosing CPI plumbing and heating!