Putting water back into a drained system

britboy4321 · 10 Dec 2008 at 14:57

Hi chaps,

I have a watercooled system. Due to a (now fixed) leak the system needs a complete refill of di-ionised water.

My question is this .. after I have added as much liquid as will fit into the reservoir (via the fillport) .. do I screw the cap on before turning the PC on for the first time?

Some people say 'Yes, the system needs to be pressurised to work so you have to ALWAYS have the cap screwed on when the pump is working'. NEVER run it with the lid not screwed up'

Others say 'No, leave it off for a while so all the air that currently in the tubes is pushed round the system, then out where the cap was (!!) (then you should be able to add some more liquid THEN finally screw the cap back on).

Any help vastly appreciated. I've fixed the leak -- but don't know how to refill the system safely....?

The Halk · 10 Dec 2008 at 16:04

I always leave the lid off my res. I can't understand people saying pressurised, where's the pressure going to come from in a closed system?

I find with the lid off it helps it get moving.

Only thing I'd say is make sure you have a PSU 20/24 pin connector thing so the mainboard isn't powered while the air gets removed.

krisboats · 10 Dec 2008 at 16:16

Given that there's no fluid in the tubing at the point of switching it on i'd say a bit of pressure from having the lid sealed would give it a hand in shoving the water and any air bubbles through a bit faster.

Undoing the lid with the system still active though in order to top it up will be absolutely fine though.

krisboats · 10 Dec 2008 at 16:18

The Halk said:
I always leave the lid off my res. I can't understand people saying pressurised, where's the pressure going to come from in a closed system?

I find with the lid off it helps it get moving.

Only thing I'd say is make sure you have a PSU 20/24 pin connector thing so the mainboard isn't powered while the air gets removed.

Think about it properly... your switching it on for the first time, water AND air will be pushed around. If the air can escape through a hole in the top of the fill tank the water will go round slower. If there's no air escaping the water shoots round quicker because the air can't escape freely

The Halk · 10 Dec 2008 at 16:18

I find the opposite, I think with the lid on it prevents mavity having an effect. But we'd need a physics graduate to work it all out

Either way works, whatever floats your boat!

I usually lay the lid half over though in case of splashes when a big pocket of air moves.

matt100 · 11 Dec 2008 at 00:41

I'd say always leave the lid off.. surely if you fill it then put the lid back on that will creat a seal the pump is pulling against?

Leave it open so you can add more water as required and to encourage air to escape through bleeding?

Never done me any harm and I've done this dozens of times now.

jjpctech · 11 Dec 2008 at 00:50

once its bled screw the res up as when its back on the water level will dop ever so slightly due to pressure from the pump.

How do i know this? cus i drew line son my ek multires and it lowers when i turn my pc on lol

ZX-10R · 11 Dec 2008 at 17:40

lid off
surely lid on will cause a slight vacuum, meaning its harder to push the air out.

w3bbo · 11 Dec 2008 at 22:42

Run it with the lid half screwed on preventing the water from sloshing out of the res but released enough to allow excess air to escape. Once the loop has been primed and bled then screw the cap down but be aware that when the water heats up, it will expand and create a pressurised system.

Personally I've not noticed any difference between a setup that's pressurised and one that isn't.

havoc08 · 11 Dec 2008 at 22:53

lid half off/on and flick tube to remove air,top up and lid on

AndyOcUK · 12 Dec 2008 at 12:15

w3bbo said:
Run it with the lid half screwed on preventing the water from sloshing out of the res but released enough to allow excess air to escape. Once the loop has been primed and bled then screw the cap down but be aware that when the water heats up, it will expand and create a pressurised system.

Personally I've not noticed any difference between a setup that's pressurised and one that isn't.

havoc08 said:
lid half off/on and flick tube to remove air,top up and lid on

Agreed - and nows the time to fit a T-line for easy draining:

http://forums.overclockers.co.uk/showthread.php?t=17950172