Here's my original problem: my maximum shower temperature has steadily decreased over several months, such that when the knob is turned all the way to hot only lukewarm water comes out. I did some reading, looked up manufacturer info (Symmons temptrol), and concluded I probably need to clean or replace the spindle or seats that are behind the cap. I bought the parts and am ready to do the job.
Step 1: shut off water supply. Here's my current problem. I can't even begin the repair because I can't find out where or how to shut off my main water supply. I've shut off the hot water, I've played with every valve and knob in my apartment with no luck. I live in a small condo so there's only so many places to look. In the basement, I see the building main supply. I see where it travels up into the ceiling somewhere unknown, and I see pipes on the other side of the building that come out of the ceiling, go into my boiler for forced hot water baseboard heating, and another split into the hot water heater. I've tried messing with every combination of knob there is and all I can manage to do is shut off the hot water.
So the question is two-fold:
1) is there someplace else I should look that I haven't yet?
2) is there any way to do this repair if cold water is still flowing to my shower?
Thanks in advance for the help,