The EcoSmart SmartPOOL 27 differs from other products we reviewed in that it is an electric tankless water heater, not a heat pump or gas heater. It is advertised as an alternative or enhancement to a heat pump like the Hayward HeatPro. There are two size options: the 18 and the 27.
Editor’s Note: This product has been removed from our side-by-side comparison because it is no longer available.
The Pentair Sta-Rite Max-E-Therm is a gas pool heater that can use either natural gas or propane. It is small and lightweight and suitable for both indoor and outdoor installations.
The HP21104T is part of the Hayward HeatPro line of electric heat pumps designed for inground pools.
Editor’s Note: This product has been removed from our side-by-side comparison because it has been discontinued.