If you want to calibrate the Z axis using manual control of HeartWare, and instead of going up it is going down (and vice versa). You can do the following in order to flip the controls.
1) Open HeartWare and click on Printer Settings
2) After having clicked on printer settings, the following tab should prompt open. Click on the Printer tab, on the top right corner.
3) Then click on Z-Axis for Invert Direction in Controls for.
4) Try using Manual Control again, the controls should have been flipped.
Please contact firstname.lastname@example.org if the issue persists.