I have a single handle Koehler shower faucet. Recently the temperature regulation has started to malfunction. The shower is ice cold until you turn the knob to the very hottest setting. Once there the water turns to extreme hot. If you turn down the knob it remains the same hot temperature until it gets to the lowest level before turning off the flow of water. At that point the water goes back to ice cold and to get any heat in it you need to turn it all the way back to the top. I can get extreme cold and extreme hot but nothing in between.
The rest of the faucets in the condo behave normally so I think something has failed in this faucet directly. I am not sure if this is something I can fix myself or if I need a plumber to look into.