You GPU card has ZERO RPM feature which means the fans won't turn on until it reaches a certain temperature.
Normally between 55c and 60c.
In Adrenaline under the Performance Tab you can bypass the ZERO RPM Feature and create your own GPU Fan Curve so that the fans will turn on sooner at a lower temperature.
I would run a game or stress test the GPU card and see when the GPU Temperature goes above 60c the fans start working.
If the fans still don't turn on when it is above 65c then you have a problem and need to start troubleshooting.