Check your thermal probe to your sentry 3 make sure it is securely connected to the unit. If the cable is at all unplugged it will ramp the fans to 100% this is a failsafe for the unit. If the plug is securely connected to the unit and the fans are still ramping at 100% then the cable itself is defective and will need to be replaced.
At this point go to support.nzxt.com and submit a ticket for a replacement.