GPA II series circulation motor pump is manily used in domestic heating and hot water system. The product is most applicable to the following systems. · Stable and variable-flow heat supply system ·Variable-temperature pipeline heat supply system · Heat supply system with night mode · Domestic heating and domestic water supply system · Industrial circulation system · Solar system · Air conditioning system Electronically controlled circulator pumps for domestic building and thermal solar systems. Shinhoo GPA II pumps are high-efficiency circulators, designed for heating and thermal solar systems. The ideal choice for basic functionality needs. Applicable as a universal upgrade and replacement pump. The pump features three constant-curve modes, proportional pressure curves, constant pressure curves, Auto and night mode. The speed can also be controlled by a low-voltage PWM signal from a controller to optimize the system performance.