Problems with the flow (1st watercooling)

Hi, it has been a long time, but here I am again...

I have finally built my first watercooling loop (it's not installed on the computer yet because while I was leak testing I've detected a problem that I want to solve before I install the blocks on the components).

My reservoir has a built in "flow meter" (somewhat rustic, a ball over the water intake of the reservoir that is pushed up the higher the more flow). When everything runs fine, the ball is pushed up about 6cm (~2.4") over the bottom of the reservoir. But whenever I power off the pump (or let the ball fall to the bottom by dropping the pump voltage to the minimum in the fan controller I have attached it to), when I give it some juice again the ball doesn't go up again (instead, it barely rises a miserable 1cm or half an inch). Indeed, the water in the reservoir looks like much less turbulent, so I suppose the pump is not working at its full potential.

It takes a completely arbitrary, random and extremely variable time to work as it should again (for example, some tests I did yesterday it recovered in a matter of seconds, sometimes it takes some minutes, today I have had to wait for more than half an hour when I tested it in the morning). I think it could be air trapped in the loop (but it has been running for more than 48 hours now! and I can see some bubbles in the reservoir, and one on the reservoir out hose, but they seem to be glued to the plastic and they don't go away), a defective pump, or even a not so useful reservoir flow meter! But I'm becoming more and more frustrated, and I don't know what to do next!

What do you think about it? What is your advise in this case?

First, what are the components in your loop?

If you think there is air in your loop, when it's running at full potential, pinch the hose on the way into your res almost closed for a couple seconds. Let it go and the bubbles should come out at that point.

The pump may also not like having its voltage reduced. Is there a reason you're using it on a fan controller?

Oh, yeah, components.

Pump: Phobya DC12-260 (rebranded Jingway DP-600P, 600 l/h, 2.6m)
Rad: Phobya Xtreme Nova 1080 (yeah, that big monster thought to be used with 9x 120mm fans, but it will be run with 4x 180mm fan that fits perfectly)
Blocks: HK 3.0 LC and MCW60-R
Res: Tecnofront Visual Trap

The pump comes with a 3-pin fan connector, it says that its starting voltage is 8V, and the fan controller I have gives the full 12V when maxed (I have not tested it, that's data from a review), so I don't think that should be the problem, but who knows. I'm running it on a fan controller because it was that or the motherboard, and the fan controller should let me adjust the flow/noise easier if needed later. At the present time, I'm running it at 12V (except when I test the re-start thing).

I will do the thing of pinching the hose now, but I don't think there's air running on the loop. I can see lots of bubbles "glued" to the plastic of the reservoir, one to a hose, and I thought it could be the same inside some components. Today I changed the rad position (vertical to horizontal) and a lot of bubbles went out from it. I don't know if it could be more inside it or in other components (like the pump itself). It would work in this case too?

Maybe a Controller problem.... simply !

Hmmm, you are making me doubt now. I will try with it plugged into the mobo, but I must say that the sound it makes when is working well its exactly the same than when it's not, at the different voltages (I mean, at 12V it sounds more than at less volts, but it's no different when the ball in the reservoir doesn't go up).

Do you think that any fan connector in my mobo (DFI Lanparty X58 UT) will work for its 8W of power consumption, or will I blow it up?

I have the more powerful version of the Phobya pump. The fan controller is most likely overheating and cutting the power, when it cools down it starts up again. I melted a Zalman fanmate with mine.

I use one of these http://www.amazon.com/s/ref=nb_ss?url=search-alias=aps&field-keywords=Zalman+ZM-MC1&x=0&y=0 connected to a molex. I generally use the 12v connector for filling/bleeding the system and have found that the pump starts and runs reliably connected to the 5v and makes it virtually silent with no noticable effect on temperatures. However as I said mine is the more powerful version and your's may not provide enough pressure on 5v.

The fan controller (a 3.5" Cooltek) it's rated for 17W per channel (4x channels) so it shouldn't be overloading with a 8W load. It only goes down when I manually unplug it or put it at its minimum power (as it should happen). The thing is that when I start it again, it doesn't push the ball up again until after a time. When it is finally working (pushing the ball 6-7 cm), it can be hours working well... it's starting what it does not good. Wow, this is quite absorbing, I'm going to take a walk and smoke a cigarette. I think a little of fresh air in the face is going to make me very good... after some hours here trapped with my WC project. I will be here soon... thanks to every body helping me!

If you have a molex -to- three pin adapter, I'd try that and connect the pump directly to the PSU. If you can unplug it and plug it back in with no ill effects, it's the controller.

One other thing that hasn't been mentioned is a faulty flow meter. If the ball and groove aren't precisely the right size, it could be getting stuck toward the bottom when you increase voltage again. The pressure increase from 0v to 12v instantly may normally be enough to jar the ball loose, but the differential from 8v to 12v may not be. Just something to consider.

in this case, i think it's best for you to connect the pump directly to three pin adapter via molex like hokiealumnus said. connect thru mobo is not a best option to use anyway...

Well, I thought I have not any molex to 3-pin adapter, but then I remembered about the Slipstreams I bought for the case being shipped with one. And yeah, they were. So now we can discard the fan controller as the source of the problem at all, because the behaviour is exactly the same connecting the pump directly to the PSU through the adapter cable. That leaves the pump (faulty or maybe not working well because of air or something...) or the flow meter.

But I can add a new symptom: this is something that happened also the day before, but I didn't give it any importance (I thought it was a more or less random thing). Until it happened yesterday also. And that thing is that in the evening, after all day running (or maybe with the heating working at home, I don't know...), it seems to work flawlessly. I can minimize voltage until it (appearently) stops working, or unplug it, even switch off the whole thing for half an hour, and then run it again, and everything works flawlessly since the first moment. 100% of times (I tried a lot of times). Then I switch it off, go to bed and at the next morning... isn't working again. 0% of the times (until an arbitrary time is passed, as always, the ball always end up where it should, it's only that it may take more than half an hour running).

Great. This is becoming more and more strange.

EDIT: I should add that when the ball doesn't go up, the ball is not the only thing that points to the pump working weaker. The coolant in the reservoir is much less turbulent when the ball doesn't go up, the surface is much more agitated (I don't know if I'm using the right word here) when the ball goes up well. So I suppose that the pump is really pushing the coolant weaker when the ball doesn't go up. The strange thing is that it sounds the same, so it seems to be running at the same speed both when it works as it should and when it doesn't...

Hate to say it, but it sounds like there are really two options - Tear the loop down and run water through every component to ensure none are blocked. (unlikely) or get yourself a new pump (more likely, based on what we're seeing so far).

Well, I have decided to test the watercooling being used on the components it has to cool, to test temps and see if this flow thing affects temps in any way, or not. And the answer is... not. Right now I think that simply the pump is not able to push the ball up but the water is flowing as it should. I think that when it's warm is easier for it to push the ball up. I've seen that if I manually turn the reservoir to let the gravity do the work, when I put it in its normal position the flow is always enough to keep the ball up. It's pushing it up to that position which it has a hard time doing, it seems.

With stock clocks, volts and everything, after 30 minutes of LinX it shows maximum temps of 53ºC/48ºC/50ºC/45ºC CPU (is it normal such a big difference between cooler and hotest cores, around 7-8 degrees?) and after 15 minutes of FurMark, maximum GPU temp is 29ºC (it's a Core i7 920 D0 and a HD5850, I'm not sure if I have said before).

That's of course with the radiator fans (4x Silverstone FN181) at maximum speed (~700rpm), pretty quiet but not silent (the pump isn't silent even with vibration damping so...). Let's see how it ends with some OC and some acoustic tunning (it will take some time because I've some things to do).

Thanks everybody for the help, and let's see along next days if finally the problem is nothing more than that.