This report describes the testing of a Nordtank prototype wind pump, NTK 3.2 WP at The Test Station for Wind Turbines, Risoe. The wind pump design is based on the Windflower-rotor combined with a piston pump through a gearbox. The tested version of the wind pump is designed for surface pumping. In the beginning of the test period some problems showed up with the functioning of the turbine. These were overcome by changing from a double acting to a single acting piston pump, and by design modifications to the yaw vane. The wind pump was afterwards in operation for four months. But not completely without operational problems. The report contains results from comparisons between calculations and measurements of the efficiency and the starting torque, some investigations of the force in the pump rod including fatigue Rainflow spectre and the behavior of the yawing system in different versions. The total efficiency in terms of water supply is quite high and comparable to Dutch CWD wind pumps, however, lower than expected from the calculated rotor efficiencies. (au) (1 tab., 35 ills., 5 refs.).