First of all. I am really sorry if this is in the wrong place. I didnt see a cooling category.
I just bought and installed a MasterCooler Nepton 280L to liquid cool my CPU. When i power it up the fans on the radiator rev up real fast and then stop. System got to the windows logo before i shut down my PC because i was nervous.
Normally with air cooling a rev and stop like that on the heat sink would be a bad thing. Can I or should i assume the same with water cooling? Or maybe the fans only kick in after the radiator needs to be cooled? I honestly dont know.
its probably just already cold and you never gave it a chance, or reason, to kick into full blast. Run an intensive task, and assuming its hooked into the right PWM fans port for the CPU on the motherboard, it will turn on when needed. i think either way the computer will/should shut itself off if it is overheating anyways, idk if thats totally true but ive noticed it on my computer and idk what is responsible for that