I couldnt get it to work and sent an email to AC and the reply I got was that they do not work in tandem. If you can I will be more than pissed. Thats what drove me to buy the Aquaero 5 before they upgraded the heatsink and two channels died, so now I have to ship it to Germany and had to buy two waterblocks. All could have been avoided if the AC4 and PA2 could work together.

If it is one of the models that support PWM you would use the fourth channel, if not any of them will do. Just remember channels 1 and 2 are thermally connected as well as 3 and 4. So if you have decent loads on channles 1 and 2, put the pump as far away (ie: channel 4) and vice versa.

I have the 800D and this problem. I can find the sweet spot and it will work for a few days, then I move it even the slightest and it returns. I have the haptick off so I dont hear the sound, but I can see the fan grafic on the fan display stutter. I will try sanding the faceplate slightly and then start messing with the tape. I was really hoping this wouldnt be so much off a hassle. Been wrestling with this thing for well over a week and now found out I have to watercool the thing to achieve my...