I must need a new pressure valve.. I don't have hot water side pressure, and I checked all other components. Can't find AquaSource faucet company - seems to be only bottled water, not shower fixtures... Anyone with experience in this area please help! Can't find new parts, etc.

Be prepared to install a new shower valve and then pull yours apart and see if you can fix the problem just by flushing everything out. If not put a new cartridge in or completely replace the valve. This time use a good well known valve like moen or kohler. Hope this helps.
Darrel

If you post picture of the faucet, we can ID it for you... But I agree with Darrel1953: flush or replace cartridge. If it doesn't help, replace entire body with some major brand name faucet.

Put in brand new and just now turned it on. Cold side not. This really make me mad. I hope Lowe's has someone to take out tile and fix the problem. How do you get the center peace out to flush. I can turn the off with the screws on either side.