Single lever shower faucet won't turn to the left.

American Standard single lever shower faucet won't turn to the left (which is supposed to be hotter but it appears to be set up backwards and is the cold side). can barely stand to take a shower because it is so hot and the lever will not turn left at all past center. I have removed the handle and see what appears to be the problem. there is a red ring with stops on it that is preventing movement to the left. I'm sure this is (hopefully) an easy fix but am afraid to proceed with out knowing exactly what to do. I don't want to make it worse. help for the non-plumber?

I don't know the specifics of that valve. Somebody here probably does. But, on some, all you need to do is remove the handle and rotate the cartridge 180-degrees and that reverses the operation. The red disk is part of the anti-scald mandate. It is adjustable. Some turn, some you have to pull out and reinsert. This probably didn't help all that much, but it probably can be returned to 'normal' operation quickly and easily with the right instructions...hold on. You could also call American Standard on Monday...they should be able to point you to the instruction sheet or talk you through how to do it if someone here doesn't help first.

The operation should be "cold first, then warm, and finally hot". If yours is the opposite the core has to be removed and reversed. Then the red stop will be positioned to limit the amount of hot water dispensed, NOT the cold.

Mine is a lever that goes left or right, not continually around but none the less I have it fixed. Thanks for everyone's help!

When you say you "have it fixed" does that mean you just adjusted it so the goes further to the left, or that you now have the cold water coming on first?