If you’re in the market for a new water heater, the first step in your search is choosing between a newer tankless model or a conventional water heater. Whereas conventional models store hot water in a tank at all times, tankless models heat water only when it is needed. Because they heat water on demand, tankless heaters do not waste heat and energy when they’re not in use. Tankless heaters are more expensive than conventional heaters, but depending on your needs, a tankless heater may make up for its initial cost through energy savings.