Can I mount my XD5 Pump/Reservoir sideways or horizontal?

While you can technically mount the XD5 RGB Elite in any direction you should want, there is multiple reasons why you should always have the pump/reservoir combo mounted in it's native vertical position.

Some positions might work if you are careful, while others, such as flipping the reservoir upside down will not work at all (and yet, there is a "but" in here, as it will technically work if you have a cooling loop where all the air is already completely out of the loop which can be incredibly hard to do).

Let's dive into some of the reasons why you will want to keep your pump/reservoir combo in a vertical position, and not mount it sideways.

If you imagine the blue line in the above picture to be the water level once you have filled up your pump/reservoir combo, then the inlet of the pump will always in in the "bottom" center of the pump/reservoir unit. In the left picture there is about 8cm of distance between the air in the pump/reservoir combo, making it very hard for the pump, even at full speed to suck air back into the pump and the rest of the loop. It also makes bleeding (getting air out) of the loop much easier because the water in the top of the reservoir is not being moved around rapidly.

In the right image where the pump/reservoir is in a sideways position there is only about 2cm of distance between the pump inlet and the water level. This can easily result in air getting sucked back into the pump as the distance is very small, and with high pump speeds the water will be very turbulent.

Should you decide on having this orientation, it is best to do the initial filling of the loop in the standard vertical position (you can flip your entire case to ensure this) and then get as much air as possible out of your loop. When you then run your pump you should try and run it at a low pump speed, as high speeds will make the water more turbulent inside the reservoir.

Another concern is that the rubber mounting nuts that you see on many pump/reservoir combo's are not made to be "pulled" on. Since the nuts in these are held in place with just the bond between the rubber and nut, you could potentially break these if the force of having the pump/reservoir combo mounted sideways becomes too much with the combined weight of the coolant, the pump/reservoir combo itself, and any additional force from tubes, moving the PC etc.

You can find out more about the XD5 RGB Elite, here.