Help! Heatsink fan is running very fast on idle!

William_larsson

Commendable
Jun 1, 2016
2
0
1,510
So I just built my first ever PC and I noticed that the heatsink fan is running very fast and loudly, even when the PC is idle. It usually runs at around 2000 RPM, even though the CPU temps are hovering at 25 C. I have a Cryorig H5 Ultimate cooler and a Gigabyte GA-Z170-Gaming K3 mobo and I'm wondering if any of these could be the issue? I have the fan connected directly to the motherboard through the CPU-fan header.

I tried to lower the fan speed in the BIOS from "Normal" to "Silent", but that only lowered the speed with ~200RPM. SpeedFan doesn't work either since it can't find the fan, even though it's a PWM fan. Gigabyte's "App Center" software doesn't work as well because it crashes as fast as I click the "Smart fan auto" feature. I have also tried to unplug and plug the connector from the motherboard without success. What could be the issue here? The fan is only rated to run at 1300 RPM at full speed and I'm worried that I'll break something running it like this.
 

William_larsson

Commendable
Jun 1, 2016
2
0
1,510
Okay so I installed the heatsink fan into one of the case fan headers and the RPM went down to about 800 RPM. Does this mean that it is a motherboard issue that is causing it to run to fans on the other header?