Hi I have an issue with my shower water temp knob. My husband is out to sea in the navy and I'm on my own to try to solve this problem. The knob for both hot and cold is a single piece. You pull it out to turn on the water and turn left for hot and right for cold. When I pull it out to turn on the water it is stuck on the max hot. It freely spins and no matter what I do it won't get cooler. It has a metal plate butting up against the shower wall and I'm not sure what I need to do to fix this problem. How do I remove it and can I just buy a new knob from the hardware store? Any help is greeatly appreciated.

Erin, hope I can help but not knowing the brand or model is a disadvantage. Any idea on the brand? Thius is likely a cartirdge shower valve. The knob should be removable, look for a small set screw on the underside or a plastic/rubber logo that is covering the screw. Once the knob is off then comes the escutcheon plate (pie shaped thing) You must have your water main shut off before we go any further, do you know how to do that?