Attempted to remove trim handle to see which moen cartridge it is. Handle would not come off. Client had already attempted with Channel locks, it had marked up the finish. Recommend calling moen and getting a complete cold side valve with trim. Give us a call and we can come back to install it. Kohler shower valve operation was working as it is designed. It has cold, warm and hot function. Client was there with me to confirm. No need at the time to replace the cartridge as the shower valve is working as it should. Clients husband can adjust the temperature by Handel location.