It sounds like the greenest idea: If you're going to boil a bag of pasta, why not fill the pot with the hottest possible tap water you have so it takes less time (and energy) to bring it to a boil? But the reality is you should never do this, because there are health risks. In most homes, hot water systems use tanks and boilers that contain metal parts, and over time, the metal corrodes and contaminates the water. Boiling water doesn't make these metals -- including lead -- go away, and they can contaminate whatever you're cooking. Always use cold water when you need to bring any water to a boil.
ANDREWS MCMEEL SYNDICATION