Our shower started leaking (hot water) when shut off about a month ago, and has streadily gotten worse. Just recently, the water flow suddenly got so low when turned on that the shower is unuseable. Since we have hard water, I assume this means replacing the inner parts of the valve (at best). This valve was installed by a plumber about 7 years ago. The cover plate says Kohler, but this doesn't look like the pictures I can find or the repair videos on YouTube. The flange behind the stem seems to be attached to what may be a screw cap on the valve body, but I put a wrench on it and it did not turn easily. Since the valve is only secured by the copper feed and output lines, I didn't feel comfortable putting any significant torque on the "cap." Since there is no shutoff valve except for the whole house shutoff, and we have 7 people in the house, I thought it best to ask questions beforeng exploratory sugery by removing the two screws visible at 3 & 9 o'clock at the base of what I think is the cartridge housing. Any help in identifying the valve and/or advise on the best way to proceed would be appreciated.