The ECO 27 is one of the most powerful models from our full line of tankless water heaters, with the capacity to handle a large single-family home and has the capacity to deliver endless hot water for multiple fixtures, even in colder climates. In warm climates, the ECO 27 can run four showers and a sink simultaneously without running out of hot water. Use the ECOSMART sizing guide to find out which model is ideal for you.