0015e3-2F4 Taco Cast Iron ECM High Efficiency Circulator, Four bolt flange. Taco 0015e3® is a variable speed, high-efficiency wet rotor circulator with an ECM permanent magnet motor. It's ideal for hydronic systems zoned with circulators or zone valves. With 3 easy settings, the 0015e3 delivers performance, reliability and ease of installation that made the 00® famous. Install it, forget it! Its ECM performance is equivalent to the Taco 0015 3-Speed circulator and is ideal for hydronic systems zoned with circulators or zone valves. The 0015e3 is not suitable for potable water or chilled water systems.