My recent kitchen renovation included a pot filler over the stove. Although I specified cold water, the contractor mistakenly connected it to hot water. Correcting to cold water now requires removing tile, opening the wall, running new pipes, etc. The contractor says it doesn't matter and that traditional advice about cooking with cold water reflects old restaurant boilers that may have been rusty. Obviously he doesn't want to fix the problem, but frankly I'm dreading the intrusion as well. How important is it to start with cold water in cooking?