I have a kohler shower head and valve (K16214-4A-BN), and some time ago it stopped delivering warm water. It will do either hot or cold but will not deliver warm water. I have warm water everywhere else in the house. The local hardware store advise that the problem was the valve so I call the company and they send me a new valve. It worked for a while but now is back to the same scenario, hot or cold only but no warm water.
Any help would be greatly appreciated.