I have no hot water in an upstairs shower but all other faucets, including another upstairs shower, have hot water. What could be causing this?

Most likely cause would be a clog in the hot water inlet on your mixing valve. The valve can be cleaned but you need to know how to remove it, do you know how? If not try to give us a picture or name/brand/model.

Most likely cause would be a clog in the hot water inlet on your mixing valve. The valve can be cleaned but you need to know how to remove it, do you know how? If not try to give us a picture or name/brand/model.

Not sure of the model # but it is a Kohler integral shut off type ( 1-lever that as you rotate controls the amount of hot or cold water)

Remove the handle and the escutcheon plate, to be safe lets close the main supply to the house for now. Spens some time at this site and see if you can find your valve. KOHLER: Showers: Bathroom (http://www.us.kohler.com/onlinecatalog/category.jsp?section=2&nsection=2&nsubsection=3&category=12&nitem=cat12)

It appears to be very similar to the Coralais Model #K-T15603.