Forget everything you know about water heaters!
Well, it’s okay to remember most of it—the only part you really need to toss out is the idea that all water heaters use large storage tanks to operate. For decades this was the standard for water heaters—and there’s still nothing wrong with relying on storage tank water heaters—but there are new models available that don’t use water tanks at all. Tankless water heaters are already enormously popular in Europe and spreading quickly in the U.S.