These circulators are popular as replacement pumps that serve a general water transfer function for residential, commercial and industrial use. Durable and capable of long service as a cold or hot water circulating pump, their rugged cast iron, open, drip proof enclosure makes them well suited for water recirculation as well as HVAC applications such as closed hydronic heating systems, water recirculation, air conditioners, and unit heaters. Brands include century and others. For other water circulator motor replacement options, see our original equipment manufacturer (OEM) replacement motors.