Upon arrival, customer showed me discontinued shower valve that they got aftermarket parts to install. The customer explained to me that the manufacturer stated that they would have to modify parts in order for them to work. I explained to customer that we are not responsible for these parts and there would not be any warranty backing up these aftermarket parts. I explained to customer that the best thing to do would be have the tile removed from the back wall to install a new shower valve. I will be getting estimates written up with management to give best valve possible to install. Customer will call after tile is removed and they will let me know if they want to change all parts out for shower to match trim of new valve or only shower valve. Also, upon inspection of water heater that is brand new, noticed emergency shut off for unit has corrosion due to valve slightly leaking and needs to be replaced before work can be done.