Ecosmart® ECO 18 POOL Smart Pool Tankless Pool Water Electric Heater 1 Phase 18 kW 240V. The Smart POOL Series can provide 1° to 1.5° F temperature rise per hour for the on demand pool heating experience. EcoSmart Pool Heaters operate by utilizing the latest flow sensor technology instead of the traditional pressure switch activation and contactors to reduce the risk of burned elements, which increases functionality and reliability. The Smart POOL Series come with digital thermostat control so you can set the temperature exactly where you want. EcoSmart Pool Heaters can be used as an alternative to heat pumps or as a booster and are compact and easy to install for a new or existing pool. The Smart POOL Series are energy efficient no matter what the ambient temperature.