What method is used to remove air from a water loop?
What method is used to remove air from a water loop?
If your pump operates smoothly and quietly, with visible flow when your PC is running normally, it suggests everything is functioning well. When you tilt the pump, air intake increases and cavitation occurs, likely causing the speed up, whining, and noise. This kind of noise and cavitation can harm the pump. Your reservoir is adequately sized, so it’s still advisable to refill it and let the system run for a day or a week—issues should resolve. If you had a T-line without a reservoir, bleeding would be more critical (a large bubble could block the pump and halt flow or trigger serious cavitation). In your setup, occasional bubbles may pass through choke points and settle, improving performance gradually. Remember that the 240 rad bubbles need to clear each section; if they accumulate, you may notice the loop’s condition worsening before fully resolving.
If your pump is operating smoothly and quietly, with normal PC performance and clear flow, it suggests everything is functioning well. When you tilt the pump, air intake increases, leading to cavitation, which likely causes the speed up and noise. This kind of noise and cavitation can harm the pump. Your reservoir is adequately sized, so it’s still advisable to refill it and let the system run for a day or a week. The issue should resolve on its own. If you had a T-line without a reservoir, bleeding would be more critical—otherwise, a large bubble could block the pump and stop flow or trigger serious cavitation. In your case, occasional bubbles passing through choke points are normal; they may settle and improve flow before the loop ends. Thanks again, BC, I’ll test it for a couple of days and let you know the outcome.
Ok, this is some additional info that was requested earlier. I think Dave suggested this, so I have taken some more pics (still not very good images I'm affraid) as well as a loop diagram (please don't judge me on my drawing abilities lol). I've had to use a torch to provide light through the colour tubing to show whether there is liquid in the tube or not. I apologise for the pics but this is the best I could manage on my own and an iPhone camera.
First and foremost here is the loop diagram;
I've highlighted the areas with red pen where the major/large air pockets are sitting and fail to move even when tilted and shaken.
This is the outlet tube of the CPU water block. Don't know if the picture actually shows it, but this whole tube is empty of liquid;
This pic is a continuance from the pic above. This tube is the same tube from the CPU Water Block and it goes into the 1st GPU. Hopefully the pic shows that there is only liquid just appearing in the bottom of the tube, therefore the other 99% of the tube is full of air;
This is the outlet tube from the top mounted 240 radiator. In this pic the tube is full of liquid, however when the case is titled from side to side the tube quickly fills up with a large air pocket that consumes about 50% of the tube's volume. In this pic the tube is full of liquid when runs to the CPU water block inlet, but the outlet (as shown above) is completely empty of liquid;
This is the tube that runs from the bottom/2nd GPU into the front mounted 360 radiator. In this pic the tube is full of liquid, but as described above regarding the 240 radiator, as soon as you start tilting the case around a large pocket of air appears in this tube and consumes anywhere from 50 - 100% of it's volume;
This pic is the tube that exits out of the front 360 radiator and starts making it's way back to the inlet port of the res/pump combo. This tube has a set of quick release fittings on it for drainage purposes down the track. It also has the flow rate meter on it, which is basically stationary despite the pump being set to full speed;
The PC has been running since I got home from work, which is about five hours now. I'll leave it running overnight and see what the results are in the morning and assess things more then.
In the meantime, if anyone has the time to look over the above diagram and pics and might have a bit more of an idea I would be very greatful.
Cheers.
It seems there was some initial confusion, but you’re not experiencing any bleeding issues. Based on what I see, you don’t have a zero flow rate; bleeding would only occur if your fluid is moving through the entire system.
Examining your hand-drawn diagram and your explanation of how it reacts when you tilt it, there appears to be a restriction in the flow.
Take a look at the tube from the pump’s outlet to the inlet of your 240 radiator. Is it completely filled with fluid? If yes, then according to your drawing, there’s a minimal flow between the radiator and your CPU block.
The reason you notice some fluid in each tube between your components is because there’s no pressure or flow behind the CPU block, so it moves through due to its own fluid weight. I strongly believe your 240 radiator might be clogged. Here’s what you could try:
1. Disconnect and form a loop using only your radiator and pump/res combo to observe the result.
2. Then attempt to flush out the radiator using a high-pressure source.
3. Repeat step 1.
From what I observe, if this doesn’t resolve the issue, it could mean the radiator isn’t working correctly and is limiting flow, or your pump might be damaged. You might want to test by connecting a long tube directly to the inlet and outlet of the pump combo to verify if the pump is operating properly.
If you ran the pump without any fluid in the reservoir, it’s likely that you’ve damaged the pump.
How difficult would it be to remove the upper radiator and connect your pump outlet straight to your CPU block just to check if that section of the loop is functioning properly?
This situation was initially a bit unclear, but you’re not experiencing any bleeding. Based on what I’ve seen, you only need to perform bleeding when your fluid is moving through the entire system. Examining your hand-drawn diagram and your explanation of how it behaves when tilted suggests there might be a restriction in the flow. Check the tube from the pump outlet to the inlet of your 240 radiator—does it contain fluid? If yes, it may indicate a small flow restriction between your radiator and CPU block. The presence of fluid in each tube between components likely means there’s no pressure or flow behind the CPU, causing it to leak fluid due to its own weight. I strongly believe your 240 radiator is clogged. Here are some steps you could try:
1. Disconnect and form a loop using only your radiator and pump/res combo to observe the flow.
2. Attempt to flush the radiator with high pressure.
3. Repeat step 1 if needed.
It seems the radiator might not be working properly or your pump could be damaged. You might want to test the pump by connecting a long tube directly from the pump combo to the inlet and outlet, just to confirm it’s operating correctly. If you ran the pump without any fluid in the reservoir, it likely caused damage.
Thanks for the advice, Dave. This seems like a reasonable plan to follow. I’ll try it out tonight and share the results.
After nearly removing the entire loop and testing each part, it seems the Phobya CPU Water Block is the issue. The pump and reservoir combination works well, delivering large volumes of water, which gives me confidence. I connected it to the 240 rad and it flowed freely without any blockage or leaks—it was a strong stream. Then I connected the same setup to the 360 rad, and the same performance occurred. I tested the CPU water block and it confirmed the problem: it was just a trickle, starting slowly before stopping completely. The product comes with no instructions at all on their website—this reveals a lack of clarity from the manufacturer. The diagram on the water block showed the inlet and outlet directions incorrectly; the arrow pointing in was actually the outlet, and the one pointing out was the inlet. This made it confusing. When I reassembled the loop correctly, the water flowed smoothly and effectively cleared out bubbles and air pockets. I wanted to thank everyone for your help—Dave and BC made a big difference, and I truly appreciate it. Finally, I can enjoy my PC again. To clarify, the original post titled "How to clear air out of water loop?" was inaccurate. The correct title should have been "My water flow rate is a trickle, how to fix?" This would have better reflected the actual issue. I now understand that flow rate and air pockets are separate concerns.
After nearly removing the entire loop and checking each part, it seems the Phobya CPU Water Block is the issue. The pump and reservoir combination works well, pushing large volumes of water, which gives me confidence. I connected it to the 240 rad and it flowed freely without any blockage or leaks—it was a strong stream. Then I connected the same setup to the 360 rad, and the same performance occurred. I tested the CPU water block and it confirmed the problem: a steady trickle, starting slowly before stopping completely. The product comes with no instructions at all on their site—this suggests the company doesn’t provide clear guidance or information about their items. The diagram on the water block showed arrows in the wrong direction; the inlet and outlet were swapped. When I set up the loop correctly, the liquid flowed through it successfully. I wanted to thank everyone for your help—Dave and BC made a big difference, and I truly appreciate it. Finally, I can enjoy my PC again. To clarify, the original post about clearing air from a water loop should have been titled something like "My water flow is a trickle, how to fix?" That would have been more precise. I now understand that flow rate and air pockets are separate concerns. Hope this helps!
You've already looked into disassembling the water block to identify the issue. It would be frustrating if there was plastic, tape, or other obstructions. You're right to be cautious about reassembly—making sure O-rings are correctly positioned is essential to prevent leaks.