[SOLVED] Need help connecting my radiator to my motherboard

Feb 5, 2022
Hi everyone
This is my first pc build and I'm a bit confused on where to plug in my radiator. I have a NZXT Kraken M22 and a ASUS Prime b560-plus as my motherboard. I've connected my fan to the cpu_fan, but i'm not sure where to plug in my radiator my manual tells me to either plug it into an cpu_opt, pump or AIO_pump. I've looked everywhere for all of those but I just cannot find it. Please help
your mainboard doesnt have optinal fan port reserved for CPU, but you have those 3 system fan headers (in disguise), just switch them to AIO pump in bios and dont forget to change monitoring for CPU on system fan you selected


Just some FYI as background. Your mobo has one CPU_FAN header and three CHA_FAN headers. All of them are able to do automatic control of your fans according to the TEMPERATURE measured at certain sensors. The CPU_FAN header always will use the temp sensor inside the CPU chip as its guide. Normally the CHA_FAN headers will use a sensor on the mobo, but some mobos allow you to re-purpose a CHA_FAN header to use the CPU internal sensor if you need that.

Exactly how you do this will depend on how many case ventilation fans (not including the AIO CPU cooler) you have. For now, I will recommend you use the CPU_FAN header only for the AIO cooler system, and reserve the CHA_FAN headers for case vent fans. But there is another way if you want that.

There are two manuals you should have. The one specific to your mobo that covers the layout and connections is here


In that, see p.1-1 for locations of the fan headers.

A general manual for several mobos to use in configuring mobo settings in BIOS Setup is available here


In that, you can start at p. 5.

Any mobo fan header has four functions. First is to provide the power to run a cooling fan or system. Second is to control that cooler to keep the temperature at its related sensor on target. Third is to read and display for you the speed of its fans (or whatever), and this is mainly for your info - it does not use that to do actual speed control. And lastly, it does monitor that speed reading to detect fan FAILURE. If that happens, it will pop up a warning on your screen so you can take corrective action. On SOME mobos (not sure about yours) failure of the fan (or pump) connected to the CPU_FAN header can prompt much more aggressive action to shut down your system completely to protect the CPU chip from dangerous overheating in the absence of any CPU cooling, and it may even refuse to let you boot up if there is NO speed shown at the CPU_FAN header.

I'm going to recommend a particular connection system for your mobo and AIO system that makes use of a couple of design quirks, and requires that you get a simple SPLITTER. That is a device with one input "arm" that plugs into a mobo fan header, and two output "arms" to plug in fans or whatever, like this


When you look for things like this the makers often mix up the labels Splitter and Hub. That unit is a simple 2-output Splitter. A HUB is a different device that has a third type of "arm" or connecting cable that must plug into a power output (either SATA or Molex) directly from the PSU. You should NOT get one of those.

You will use that Splitter to connect to your CPU_FAN header both the pump and the fan of your Kraken M22 system. Look closely at the two output arms. Only ONE of them has all four pins. A mobo header can work with the speed signal coming back to it from only ONE fan, so a Splitter will send back to its host header ONE fan's speed using the output with all four pins, and ignore the speed signal from any other fan by omitting Pin #3 in other output arms.

Now, note that the cable from the PUMP unit ends in a fan connector with THREE holes. The pump is wired like an older 3-pin fan. One design quirk of the new 4-pin fan system is that, when you plug an older 3-pin fan into a 4-pin header that really is using the new PWM Mode to control its fan, that older fan will always run full speed with no control. As it happens, that is exactly what the PUMP in an AIO system is for - to run full speed all the time. So, you should plug that cable from the PUMP into the one Splitter output arm with all four pins, and the FAN on the rad into the other Splitter output arm. We will ensure the header uses the PWM Mode setting. Doing this means that the PUMP will always run full speed AND that its speed WILL be measured, displayed and monitored for FAILURE. In an AIO system, the most important item foo failure monitoring is the pump - no pump operation gives NO heat removal. The RAD FAN, on the other hand, WILL have its speed controlled this way because it is a 4-pin PWM fan design, BUT its speed will NOT be seen ever by the CPU_FAN header. So YOU will need to check from time to time that that rad fan still is working. Note that the PUMP unit also has a cable you must connect between it and a mobo USB2 header, and that you need to download and run the NZXT utility CAM. That utility uses the USB cable to communicate with the pump. It can show you speed readings for BOTH the pump and the rad fan, and it will control the rad fan speed as needed for cooling. It MAY (I do not know for sure) include a means of monitoring the rad fan for failure.

With that in place, you now have all three of your mobo CHA_FAN headers free to use for case ventilation fans.

Onward to BIOS Setup tools - see the BIOS manual p. 5 to start at how to get there. You do this by pushing the "Del" key immediately after starting up. I find it best to hold that key down (so that keyboard signal is "seen") until the opening screen shows (see p. 6.) There use the F7 key to access Advanced Mode (p. 7). There choose Monitor at top to get to p. 44, where you can choose QFAN Configuration to get to p.46. From here you can choose individual fan headers to configure separately. Choose first the CPU_FAN header. For MODE, set to PWM, not Auto or DC. For the Profile set to Standard. You don't need to change any other settings for CPU_FAN.

Go to each of the CHA_FAN headers and set them. For MODE, set to PWM if the case fan plugged in there is 4-pin, or to DC if the fan is 3-pin. Set Profile to Standard. Set the Source for his fan to Motherboard (the temp sensor on the mobo). After you have set those for all CHA_FAN headers, use the Esc key to get back to the Monitor menu (p. 44), and choose Exit at top right - see p. 61. There choose Save Changes and Reset to save your settings and reboot.

This will set up your Kraken M22 CPU cooler system to control the CPU cooling automatically and monitor the pump for failure, and set your mobo CHA_FAN headers to control all your case ventilation fans automatically based on the temperature on your mobo.
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