CPU Fan error?

Hey, just booted up my PC today for the usual
This time it came up differently, Saying CPU Fan Error, F1 for set up

I pressed F1 which then took me to the BIOS, i absolutely have no idea what to do here but what i have noticed for the past few days or maybe the first time i tooked a step into the BIOS, was one of the fans called CHA FAN2 or something which bar was red

i didn't really do anything on the BIOS just booted my INTEL SSD to load up windows, doesn't seem like anything changed, doesn't seem worrying at all.

EDIT:

I rechecked my bios and it does look like CHA FAN2 is running really slow
CPU Fan - average 745-800 RPM
PWR Fan - average 4200rpm
CHA FAN1 - 820 RPM
CHA FAN2 - 518RPM

The red bar on the chassis fan probably just means that it was spinning below the threashold set in BIOS. There's an option to warn you if a fan drops below a certain speed but different fans have different minimum speeds so you can change the value at which you get that warning BUT only if you check first to see that the fan is actually spinning.

On that note, have you enabled any of the Q-Fan settings - the ones that allow the motherboard to control the speed of the fans to reduce noise when the PC is cool?

Regarding the CPU fan...

You normally get that warning if the CPU cooling fan either stops spinning or is regarded as spinning too slowly - it stops you from booting to prevent the CPU from overheating. As with the chassis fan, the motherboard has a limit and if the fan spind slower than that, it flags up this warning. By default on your board, you'll get that warning if the CPU fan goes below 600rpm. It's very likely that your CPU fan is just spinning a bit below 600rpm when the PC is cold and everything's fine - we just need to change the level of the warning BUT we need to make absolutely sure that there isn't actually a problem and the fan isn't working correctly.

What you need to do is check to see that the CPU fan is actually spinning. Start the PC but don't let it boot beyond BIOS. If the fan isn't spinning, switch the PC off and post back - do not boot into Windows or you could damage your CPU. If it is spinning, go into the Monitor section of BIOS (where you saw the red bar for the chassis fan) and check to see what rpm the CPU fan is spinning at - then post back with the details.

[Edit - you editted your post whilst I was typing. 500rpm for a chassis fan is fine - if you are using the Q-Fan settings (an any application or hardware to control fan speeds. Without knowing that, the spin-speed on its own is meaningless]

Thanks for your help as always pengipete

I've checked and made sure that every fan is INDEED working, Even the radiator as i am using an ECO ALC 240 cooling which is watercooling so am unsure as what it meant by CPU Fan
I am not using any Fan settings at all as i've not changed anything fan based. In the BIOS the CHA FAN2 is the only thing that is red bar
My room is damn cold so this could be a reason?

In the Monitor section of BIOS, look where it says CPU Q-Fan Control and Chassis Q-Fan Control - what's written in those boxes?

On bios - Monitor
CPU Q Fan control - ENABLE
CPU low speed fan limit - 600RPM

Chasis Q Fan control - ENABLE
Chasis low speed limit - 600RPM

If low limit is 600RPM doesn't that mean its not suppose to go under 600RPM? correct me if im wrong