Well, there would appear to be two possible causes to your problem. The most desirable would be that the cable has deformed so that when the knob is pushed all the way in the valve is not totally closed. This could be checked by disconnecting the cable from the lever and seeing if the lever can be moved over farther. The more likely cause is that the water temperature control valve is not closing completely regardless of where the lever is placed. This would require replacement or repair of the valve-replacements are not easily found and $$. Seems someone had an article in the quarterly once about how they could be repaired, but no idea when. In the couple of 100 thousand I've put on Kaisers, I've never had a valve fail, but it seems that once the cable wasn't closing it all the way, so that would be the first thing to check. Bon chance.