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Water Temp impacting Flow Rate?

bjcsoln

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Do you actually observe this outside of what the flow meter tells you? A drop of 5L/min should be noticeable in your reservoir or a block if you look carefully with a flashlight.
JD - what exactly should I be looking for? The fluid is clear so I wouldn't know what to look for.
 

JD

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Is this still how it looks? https://hardwarecanucks.com/forum/threads/mercii-1-update.82002/page-4

If there's still an air pocket at the top of your reservoir, don't you see some agitation in the water? If there isn't, maybe drain a bit.

Do you still have all those fittings too? It looks like you didn't buy the EK Reservoir with the direct-attach DDC mount, it looks like you have your DDC below? Wondering if the pump isn't getting a continuous feed of water either.
 

clshades

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Easy trouble shooting step. Open your fill port and run it hot and cold. See if the flow rate is still affected. That at least eliminates a pressure problem related to heat differences.

Assuming this is even possible to do.
 

bjcsoln

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Is this still how it looks? https://hardwarecanucks.com/forum/threads/mercii-1-update.82002/page-4

If there's still an air pocket at the top of your reservoir, don't you see some agitation in the water? If there isn't, maybe drain a bit.

Do you still have all those fittings too? It looks like you didn't buy the EK Reservoir with the direct-attach DDC mount, it looks like you have your DDC below? Wondering if the pump isn't getting a continuous feed of water either.
JD, actually that's the old version, but generally it looks the same (granted I added a bunch more fittings before the pump). Right now the air pocket at the top of the res is pretty small so most of the agitation really only happens near the bottom. I can drain it down temporarily to see if I can noticeably see changes in the agitation based on lowering flow rate.

As per your comment about the pump maybe not getting a continuous feed of water (which may impact the flow rate), I could see that as a possibility, however if I leave the computer running (and turn off the miner so the fluid temps drop back down to 35) then the flow rate increases and stays at the max level.

@clshades I did remove the port on the top of the res (so to eliminate and pressure issues) - that did not make an impact on the flow rate (as in it did not improve the flow rate when the water heated up and the flow slowed down). Other note - looking at the docs this barrow is impeller driven, and I can also watch (according to the LCD display on the flow meter) the RPMs of the impeller slow down with the flow rate (which makes sense).

Other random stuff - my MOBO is reporting that that pump RPM is staying constant (I do have it set on max, but was wondering if somewhere some software decided to reduce it just for the heck of it)
 

JD

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Have you tried disconnecting the pump from the motherboard? Most pumps will run at 100% without PWM signal. I suppose its possible the motherboard is sending it a bad PWM signal but I would expect the RPM of the pump to drop too.
 

bjcsoln

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Have you tried disconnecting the pump from the motherboard? Most pumps will run at 100% without PWM signal. I suppose its possible the motherboard is sending it a bad PWM signal but I would expect the RPM of the pump to drop too.
Good idea JD - I will try that. But to your point, I also would expect the pump RPM to drop (in parallel with the flow rate and impeller RPM dropping) but either way its worth a shot
 
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