Help with watercooling

123456789 · 11 Nov 2006 at 11:55

i have a bit of a problem and i was hoping someone could help me. i apologise if this question has been asked before but i have looked and couldnt find anything

the question i have is

how do i start my watercooling before my pc actually starts.

I have read you can bypass the molex cable that plugs into the motherboard to get things started before the actual pc starts. (but i have lost the link)

i was hoping to be able to connect a switch so that i can turn the watercooling on then the pc on if that is at all possible.

ichabod crane · 11 Nov 2006 at 12:39

you need to hot wire your PSU, just connect the pump and maybe a few fans to it, some need a bit of wattage to kick start them. then place a paper clip or some wire in the green and black slots on the 24pin mobo connector should fire up then and just run the pump

Hades · 11 Nov 2006 at 12:44

Or if you're not confident enough to hotwire it (which is very easy) then you could buy a PSU tester for less than £10.

123456789 · 11 Nov 2006 at 13:12

if i was to hot wire it how would i add a switch so that i can controll if the watercooler is on or off?

DaveMac · 11 Nov 2006 at 17:21

123456789 said:
if i was to hot wire it how would i add a switch so that i can controll if the watercooler is on or off?

Use the main PSU switch.

gr1mey · 12 Nov 2006 at 09:33

or you can buy a pump relay card, Ive got one, it enables you to turn the pump on without turning the rest of the PC on, and with the flick of a switch changes it so that the pump will turn on when power is sent through the motherboard...

weescott · 12 Nov 2006 at 11:40

Why do you need to have your watercooling start before your PC?

pastymuncher · 12 Nov 2006 at 13:58

You could get a AT switcheable psu which is what i run my loop and rad fans from. They only cost a couple of quid from a auction site. Most of my water cooling components (aside from the blocks) are external to the pc though.

The benefits being:-
1. Super easy leak testing and bleeding.
2. Able to leave the loop running after the pc is switched off to continue lowering temps. Supposedly giving your components longer life. Argueable i know but it sets my mind at ease.

I believe there is a relay available to connect your pump to which enables you to run the loop without the pc. I sits in a pci slot. Can't remember who makes it though.

2bullish · 12 Nov 2006 at 15:45

If you have more than one comp in the house just plug your pump into one of the 12v rails.

123456789 · 13 Nov 2006 at 10:10

weescott said:
Why do you need to have your watercooling start before your PC?

i thought if i had the watercooler on before the pc it would give me better temperatures than if i was to just start the watercooler when the pc starts

i could be wrong though

weescott · 13 Nov 2006 at 11:56

123456789 said:
i thought if i had the watercooler on before the pc it would give me better temperatures than if i was to just start the watercooler when the pc starts

i could be wrong though

You are indeed wrong.

If there was better temperatures then it would be negligable and short lived.

Marci · 13 Nov 2006 at 12:41

K... with PC System and watercooling switched off, the ambient air in the room is free to flow wherever it likes, thus returning water to ambient temps.

Fire up watercooling alone, no pc... the air being blown thru the rad is the ambient temp of the room. Thus water remains at ambient temps.

IE: No heatload exists to be cooled until the PC is fired up. The water-rig does zero work at all until the PC is switched on. All you serve to do by firing water-rig up before PC is dump the pump's heat into the coolant, and remove it again with the radiator... so the water will always be at the same temp regardless of wether the rig is switched on before the PC or at the same time as the PC.

Therefore, whether water-rig is on or not before PC makes no difference at all.

If you MUST have watercooling on before PC, sell your 12v pump and buy a 240v pump, and leave it plugged into the wall and switched on 24/7. Ignore folks advising relays and suchlike. They only work with 240v pumps, not 12v pumps, which I get the impression is what you have, otherwise it wouldn't be hooked up to PC PSU to start with.

SpudMaster · 13 Nov 2006 at 20:17

yeah unless your leak testing theres no need to run the watercooling when the pc is switched off

ted34 · 13 Nov 2006 at 22:01

I made this a while ago:

http://forums.overclockers.co.uk/showthread.php?t=17574789&highlight=relay

I have a switch on mine so i can bypass relay and run pump when comp off for bleeding

123456789 · 14 Nov 2006 at 09:48

Marci said:
K... with PC System and watercooling switched off, the ambient air in the room is free to flow wherever it likes, thus returning water to ambient temps.

Fire up watercooling alone, no pc... the air being blown thru the rad is the ambient temp of the room. Thus water remains at ambient temps.

IE: No heatload exists to be cooled until the PC is fired up. The water-rig does zero work at all until the PC is switched on. All you serve to do by firing water-rig up before PC is dump the pump's heat into the coolant, and remove it again with the radiator... so the water will always be at the same temp regardless of wether the rig is switched on before the PC or at the same time as the PC.

Therefore, whether water-rig is on or not before PC makes no difference at all.

If you MUST have watercooling on before PC, sell your 12v pump and buy a 240v pump, and leave it plugged into the wall and switched on 24/7. Ignore folks advising relays and suchlike. They only work with 240v pumps, not 12v pumps, which I get the impression is what you have, otherwise it wouldn't be hooked up to PC PSU to start with.

thank you for clearing up the temperature thing,

Also are you saying that i dont need to hotwire my PSU all i need to do is plug the molex cables from the pump to my PSU and use the power switch on the computer case

Sorry if these are stupid questions but i dont want anything to go wrong and i dont want to do unnessasary work

Marci · 14 Nov 2006 at 10:48

Hotwire your PSU to fire the pump up for leaktesting purposes... once leaktesting done, remove hotwire, plug everything back in to mobo. Turn on PC and pump will turn on automatically.