The toilet. The john. The loo. The commode. The porcelain throne. No matter what you call it, there's no doubt it's a true technological marvel. Look beyond the commonplace bowl and see what a sophisticated water-handling system your toilet is.
You probably don't give it much thought until the shower goes cold, but water heaters are part of our daily lives. Find out how these ever-important appliances produce hot water -- and what may be wrong if they don't.