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D5 Pump Not Strong Enough?

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turok_t

Registered
Joined
Nov 12, 2009
Hi everyone, I just got a Singularity Computers Protium D5 reservoir and an alphacool VP655 D5 PWM pump. I?m testing them out of my system to make sure that the pump works fine before installing it in my build. Water travels from the radiator up to the inlet of the pump/reservoir and then it leaves the pump into the green tube (testing only) going back into the radiator. My question is this, there is a huge air bubble in the green tube close to the outlet of the pump and it looks like the pump isn?t able to pump the water strong enough causing the massive air bubble. It looks like water is just trickling down the green tube. Is this normal? I made a video and posted it in the link below.

At first, I thought this might be caused by the 90 degree inlet bend restricting the water flow into the pump. But then again, the pump is gravity fed by the reservoir so there is plenty of water feeding the pump and this shouldn?t be a feeding/intake problem.

I tried using a different D5 pump (Laing D5T Vario) and I get the same result. I also tried a different PSU (EVGA 850W) and get the same result.
So is that massive air bubble normal when water is leaving the pump? Or do I have to wait for it to naturally bleed itself out of the loop? I?m worried that my pump isn?t strong enough, but then again, I know D5 pumps can push through a lot.

Any comments/suggestions would be helpful, thanks.

20210614-160712.jpg

 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Cycle it on/off a lot... tilt the system to get more bubbles out/bleed it.

It's 100% speed, yes?
 
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turok_t

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Nov 12, 2009
Cycle it on/off a lot... tilt the system to get more bubbles out/bleed it.

It's 100% speed, yes?

Yeah im assuming its at 100% speed, i didn't connect the PWM connector yet as im powering it outside of my system for testing at this time. I only connected the pump's molex to the PSU, so im assuming its at full speed. Do you know why the water would be trickling out of the outlet tube?? or is the flow being blocked by a giant air bubble that needs to bleed out of the system?
 

Voodoo Rufus

Powder Junkie Moderator
Joined
Sep 20, 2001
The PWM pumps will run 100% if not connected to a PWM header. Perhaps the pump isn't primed well enough. Trying adding more water to the reservoir, and cycling the power on and off a few times. And do the 'radiator dance'.
 
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turok_t

Registered
Joined
Nov 12, 2009
do you guys pretty much just tilt and rotate your computer case? When i did soft tubing before, i could flick the tubes and the air bubbles would be lodged from the tube and flow in the circuit, but its harder with hard tubing now.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Yeah im assuming its at 100% speed, i didn't connect the PWM connector yet as im powering it outside of my system for testing at this time. I only connected the pump's molex to the PSU, so im assuming its at full speed. Do you know why the water would be trickling out of the outlet tube?? or is the flow being blocked by a giant air bubble that needs to bleed out of the system?
Thats what I said, yep. Power cycle the pump several times... flip system around, etc...jm thinking it's akr in the system.
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Yes, tilt it every which way you can and shake it. With the top of the radiator higher than the top of the res you will get bubbles trapped in there while bleeding. I would fill the res up a little more then leave the port on the top of the res open while slowly tilting the whole thing around. I like to give the air an escape then refill as needed as I slowly rotate it. I also turn the pump on and off while it is tilted in various positions to let air build up then flow out as I turn it back on. Once I feel most of the air is out I leave the port open slightly then let it run over night to get all the little bubbles out.
 
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turok_t

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Nov 12, 2009
Yes, tilt it every which way you can and shake it. With the top of the radiator higher than the top of the res you will get bubbles trapped in there while bleeding. I would fill the res up a little more then leave the port on the top of the res open while slowly tilting the whole thing around. I like to give the air an escape then refill as needed as I slowly rotate it. I also turn the pump on and off while it is tilted in various positions to let air build up then flow out as I turn it back on. Once I feel most of the air is out I leave the port open slightly then let it run over night to get all the little bubbles out.

That's a very good point, thanks! Now, my radiator is higher than my reservoir, so im guessing as i fill in my reservoir, the radiator will be filled up to the same level as well. However, once i fill my reservoir to the max, there is still a gap at the top of my radiator. Will this part be filled as well as the pump pushes the water in? or will the water level of the radiator remain the same as the reservoir?
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
It will but the air will still get trapped in there. The tilting and shaking will free it up to move as you do it though. It just takes time to get it all out. It took me most of a day of on and off tilting, powering on and off and an overnight run to get all the air out when I built my current loop. At least yours is out if the case. I had two radiators the res and blocks in a huge Enthoo Primo to muscle around.
 
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turok_t

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Nov 12, 2009
It will but the air will still get trapped in there. The tilting and shaking will free it up to move as you do it though. It just takes time to get it all out. It took me most of a day of on and off tilting, powering on and off and an overnight run to get all the air out when I built my current loop. At least yours is out if the case. I had two radiators the res and blocks in a huge Enthoo Primo to muscle around.

Here is a picture of my build actually. I took out one of my radiator and pump/reservoir to test it out since there was a leak. Anyhow, you see how i have a horizontal radiator at the top? im worried that water can't fill that radiator completely since it is at the highest point.
20210614-113847.jpg
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
You are correct but as you tilt it the water will flow there just fine because it will push the air out. Looks good, nice and clean.
 
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turok_t

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Nov 12, 2009
Alright, I think I fixed it after some testing today.
Here is a video of the pump spinning, notice how its spinning quite fast and generating a lot of air bubbles? The air bubbles are then fed back out from the pump into the water loop. Also, notice how loud the pump is? With all the pumps I used in the past, it never sounded this loud.


After connecting it to a separate computer, this is how my pump sound like now. ItÂ’s completely inaudible (the background noise you hear is from the computer at the back). There are minimal air bubbles in the reservoir and inlet and outlet tubes from the pump. This is how quiet I am used to with my previous pumps. When I went into the BIOS, my pump was spinning at 1800RPM (Normal Speed). If I increased the pump speed to 4787RPM (Full Speed), I can replicate the loudness in the first video which sounds like a turbine. I also tried used a different inlet (top of my multi-port cap) on my reservoir and the water seems to be flowing well and not trickling or splashing back in.


So all in all, it was indeed the pump speed/RPM. After modulating its speed, there are less air bubbles, less turbulence and the pump is much quiet now. I still did do a lot of tilting and rotating to bleed out the air bubbles as much as possible, but this looks and sounds much better than before. IÂ’m more confident with my pump now and will reinstall it back in my system.
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Air in the line doesn't just disappear so I would be worried it is sitting In a radiator corner or block somewhere. The tilting could have got a bunch out but it is better to find it now than when it gets stuck over your core and overheats it.
 
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turok_t

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Nov 12, 2009
Tried to watch the vid, but they are private.

Hey sorry, the links are back up now.

- - - Auto-Merged Double Post - - -

Air in the line doesn't just disappear so I would be worried it is sitting In a radiator corner or block somewhere. The tilting could have got a bunch out but it is better to find it now than when it gets stuck over your core and overheats it.

Yeah, im so glad I found out this problem before i installed it in my rig, so now I know what to do when i put everything together in my rig. Once everything is installed in my case, going to tilt/rotate as much as possible to bleed out those air bubbles.
 

Voodoo Rufus

Powder Junkie Moderator
Joined
Sep 20, 2001
Yeah, it looks like the pump isn't fully primed. Need to get the air bubbles out of the impeller area. Once you get real flow, it'll be obvious.
 
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turok_t

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Nov 12, 2009
Sometimes the water flowing is so quiet and still it just looks like its sitting in the tubes and reservoir and i wonder if it's actually flowing. I'm sure it is as I see some small bubbles being pushed through the loop, i see the impeller spinning and when i put the inlet valve at the top of my multi-port, i can see water flowing down. I can always hook up my digital flow meter to verify that it is indeed flowing. But I remember that this is normal when the water flow looks really still in the loop.
 
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turok_t

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Nov 12, 2009
Hi everyone, here is an update on my build. Pump and reservoir has been installed back into my rig and IÂ’m just leak testing everything. So far, there are no leaks, however, IÂ’m wondering if my pump flow is being restricted. As you can see from the picture below, I have a sharp 90 degree angle as the pump outlet, and sharp 90 degree angle as the pump inlet. IÂ’ve seen other builds with these angled fittings, so I thought it would be okay. Would the 90 degrees outlet restrict the water coming out of the pump? The reason why im asking is because I have a flow meter right after the water leaves the pump and it is showing 10 revs/second and 0.4L/min which is really low, especially when the pump is on full speed at 4700 RPM. My flow meter works perfectly as I tested it out before on my other rigs. On my other rigs, when my D5 Vario was on setting 3-4, it would show 40 rev/sec and 1.8L/min. But now on my D5 PWM pump it is showing much less flow at max speed. I also included a video of this at the bottom too, along with my entire water loop. I have a CPU and GPU waterblock and two 360 rad.

20210715-1837188.jpg
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Here is the video: