Examine the hardware carefully for a manufacturer's sign. Check all areas of the valve, looking for the Kohler logo. The logo features the company name in capital letters with a copyright mark on the right side. It may have a dark background with lighter letters or dark letters against a light background.
Pull off the plate, knob or any other hardware on the shower valve. Even if the outer plate says Kohler, there's no guarantee that the valve itself is a Kohler, as someone may have used products from another company with the new hardware. Check the valve for the Kohler logo.
Remove the shower valve from the shower and take it to a hardware store. Look at the Kohler shower valves for sale and find one that matches or one that has a similar shape and size. If it's an older piece, the store may not have an exact match.
Compare the shower valve against those offered for sale on the Kohler website. The site lists the top sellers in the shower valve category and those still made by the company. Each piece has a full-color image, which you can compare to your valve.
Look for a model number or any other identifying marks on the shower valve. Contact Kohler Customer Service directly at 1-800-4KOHLER and ask about identifying the valve. Tell the customer service representative that you're having problems and need a new piece, but aren't sure what type of shower valve you have.