Tankless water heaters have become very popular in recent years mostly because of the ‘green’ movement. They work by heating the water as you use it, rather than keeping a tank of water warm. When you turn on the hot water tap the cold water goes into the unit and is heated immediately.There are many opinions about these heaters and many pros and cons. You can save money on energy bills and they also last longer than a tank heater. A tankless heater takes up less space in your home. However they do cost more to purchase. A tankless heater is limited in the amount of out flow. You may require more than one for a large household. They are much more energy efficient, saving on your heating bill. So the choice really depends on what you prefer.