First water loop issues
First water loop issues
Hi everyone. I recently assembled my very first custom PC desk featuring a water loop. This is my initial attempt at building a PC with a water loop. My CPU is idle around 33°C when fully loaded, but with CPU-Z it spikes to about 88°C, which feels quite high. The dual GPU is running at 27°C idle and mid-40s at full load. Also, when I shut down the PC, the cooling tube appears to empty completely—something that seems unusual. I’m not sure if my pump isn’t powerful enough or if there’s another issue. Could anyone assist me?
System specs:
Asus Strix X99 Gaming
I7 6800K
Sli Strix 1080
32GB Corsair Dominator DDR4
2 x 360mm radiators, 1 D5 pump, 2 EWATER blocks for GPU and an EK Supreme EVO block on the CPU. I’m using roughly 3.5 meters of tubing.
Thank you in advance.
https://flic.kr/p/RAnQz1
https://flic.kr/p/Si2jPj
Well, here are a few suggestions to address some of the issues in this loop:
1. Three reservoirs seem unnecessary—they offer no real practical or cooling advantage and actually increase flow restriction because of many extra 90-degree turns. Consider an alternative solution if that’s your intention.
2. Link the GPU blocks in parallel—both connectors should connect, using the port nearer the outputs and the other for the inputs.
3. Prevent long back-and-forth paths. Direct the GPU blocks straight to the CPU block; the connection order doesn’t matter much.
4. On the radiators, set the lower port as an inlet and the upper port as an outlet.
Implementing these changes will significantly improve the flow in your loop, enabling much better performance.
Ben_185:
Hello everyone. I just assembled my first custom PC desk with a water loop. This is my initial PC build using a water loop. My CPU is idle around 33°C when fully loaded, but cpu-z shows it reaches about 88°C, which feels quite hot. The dual GPU are running at 27°C idle and mid-40s at full load. Also, when I shut down the PC, the tube from the CPU seems to empty completely, which I don’t think is supposed to happen.
I’m not sure if my pump isn’t powerful enough or if there’s another issue. Could anyone help me?
System specs:
Asus Strix X99 Gaming
I7 6800K
Sli Strix 1080s GPU
32GB Corsair Dominator DDR4
2 x 360mm radiators, 1 D5 pump, 2 EW water blocks for the GPU and an EK supremacy EVO block on the CPU. I’m using around 3.5 meters of tubing.
Thank you in advance.
You might need more air in the line (meaning you should fill and bleed the tubing, radiators, and blocks properly), possibly too much or too little thermal paste on the CPU, and/or the CPU water block isn’t seated correctly. Ideally, having two loops would be better for longer runs. Make sure the length of the loop doesn’t exceed what the pump’s head pressure can handle. If it does, you won’t move any water effectively. Also, keep in mind that more bends and turns increase resistance, including within the water blocks, which reduces the pump’s efficiency.
the 88 is actually too high, particularly for "light" load when using CPU-Z. A few pictures would be useful to clarify possible problems and recommend fixes. Initially, tubes shouldn't empty out after turning off the pump; only air pockets should remain in the loop, ideally in the reservoir. The idle CPU temperature is also a bit elevated, likely similar to GPUs (definitely not a 6°C difference). This could result from excess air inside the CPU block or improper mounting. Another cause might be insufficient liquid flow within the CPU block. Your loop setup is fairly complex, with many flow restrictions—each component and every 90-degree turn adds to the restriction. Even the orientation of the CPU block can impact cooling performance. It would be better to connect GPU blocks in parallel and sequentially to the CPU. Running the pump at full speed is recommended for your situation. Consider reviewing your setup and share some images if you need more help.
^1 The system hasn't been completely drained of air yet.
Without photos it's tough to determine the optimal method for bleeding, but a simple approach is to run the pump at full speed and gently shake the entire unit—side to side and back to front—to dislodge any trapped air bubbles.
I've added two photos of my loop. It seems my tanks aren't filling completely, is that the problem?
Also please disregard the incorrect pump indications in the photos. I've corrected them. Thanks
Ben_185 suggests confirming the setup is complete, using a second pump in the loop to handle pressure, ensuring blocks are properly seated, and placing the pump lower than the reservoirs for easier water access.