The 00 ® Series Variable Speed Outdoor Reset Circulator controls the hot water supply temperature, so that the heat supplied to the building equals the heat loss of the building. It modulates the Circulator to inject hot water from the boiler loop into the radiant or reduced temperature loop while providing outdoor reset to a heating system. Available in any style 006 – 0014, the 00 ® Series Variable Speed Outdoor Reset Circulator also comes with a boiler sensor to protect against low return temperatures. The 00 ® Series Variable Speed Outdoor Reset Circulator is the ultimate for protection, control, ease of installation, and trouble-free operation.