• ×
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.Windows 11 Support Center.
  • post a message
  • ×
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.Windows 11 Support Center.
  • post a message
The HP Community is where owners of HP products, like you, volunteer to help each other find solutions.
HP Recommended
HP Omen Obelisk 875-XXXX
Microsoft Windows 10 (64-bit)

I searched for how to install a liquid cooling system for the HP Omen Obelisk 875 series. Not a lot of information and worse, there is some misleading information. In an effort to help others I am creating this post. 


Any 120mm cooling unit SHOULD work. That is because the top area used for the radiator is 120mm. I used the Corsair H60 for my build and it worked out well. Do your research, there are many options to choose from. Find one that is right for you and how you use your rig. I will provide a small review of the H60 below.  


Here are the steps to install a liquid cooling system. This will be from my experience with the H60, if you get something else the steps may be slightly different. 


*IMPORTANT* If you decide to use the H60 you have to use a SATA power connection. There is an extra SATA power connector but if you used or use it for something else you will need to split it. I did have to split it since I installed another HDD in my case. 


  1. Remove the current heat sink from the processor. Unscrew the fan, remove it. Then unscrew the heatsink and then give it a small twist and pull from the processor. Once you unscrew it, the only thing holding it in place is the thermal grease. 
    1. Clean the old thermal grease off the CPU. Use rubbing alcohol wipes and do not get any liquid on the motherboard. Using premoistened towelettes is a great idea. Go slow.
    2. Save the heatsink, just in case you need it in the future. For example, if your liquid cooling unit fails. 

  2. You are going to need to pull the system apart. From my understanding the back side cover does not come off, just the clear side does. The reason you have to take everything apart is to remove the current heatsink brackets. *You might be able to find a liquid cooling unit compatible with the current brackets, I could not. 
    1. The breakdown is easy and straightforward. Take lots of pictures as you take everything apart for reference. Go slow and take your time. 
    2. When you get everything unscrewed the motherboard sticks a little by the backports (USB, Sound, etc). Take off the PCI plat strips and just slowly unwedge the motherboard. Go slow, be careful, take your time. It will pop free. 

  3. Once you get the motherboard off flip it over and you will need to slowly pry the bracket off the back of the motherboard. It is plastic and glued to the metal plate, again on the back of the motherboard. I used a small pocket knife (it is really small, blade is almost 2 inches) and just slowly ran it between the plastic and metal plate. In a slicing motion little by little and stabbing it in just a bit when there was a tough part. Go slow pry it off. 

  4. Once the old bracket is off, you can install your new bracket. Each brand is different. The H60 took a little work to get on, again take your time and do not tighten anything until it looks and feels good. 
    1. Make sure you get the bracket on snug. I did not and when I tightened the liquid cooling unit (last step) there were some popping noises that scared the crap out of me. The popping for me was the back bracket popping into the motherboard slots. I did not press it in far enough, so the tightening did it for me. 

  5. Put the motherboard back together and use those pictures you took if you lose your way. This step is easy just make sure the cables stay nice and neat so you have good airflow. 

  6. Now mount the radiator. There is a top plate that has two screws on the left and right. This is the plate with the four boxes and pluses in the middle of each. Take that plate off and pop out each box. Just apply a bit of pressure, they pop out easily. Each four need to be popped off. Mount the radiator to this bracket, it will be on the inside of the case. This is why you can only use a 120mm system, that is what the bracket supports. 

  7. Install the fan to the radiator. Corsair says to install the fan as an intake which is not a good idea. That would prioritize CPU cooling but at the cost of heating your case and stressing you gfx card even more. I highly recommend installing the fan as an outtake, it should blow air up and out of the system. Your CPU cooling won't be as strong but your motherboard and gfx card will thank you. 

  8. Once the radiator and fan are connecting mount the bracket back onto the top of the case. Two screws and you are set. 

  9. Mount your liquid cooling unit to the processor and tighten. You may hear a pop if using the H60 and you didn't push the back bracket in. Everything should be ok...should and it will scare you a bit 🙂

  10. At this point, you should be ready to rock. Give everything a quick look over, make sure all looks good. Power the system back on. 
    1. At this point, I got post errors (series of beeps). I was sure I broke something, but after I powered it down and back on everything worked. Not sure what the deal was with me, I think it had to do something with power since I had to split two SATA connections to power the liquid cooler and another fan. 

  11. OPTIONAL. The cooling of the HP OMEN Obelisk 875-XXXX isn't ideal, but it isn't bad. The reason it isn't ideal is that they didn't allow for any front fans. It would be great to have 3 fans in the front with filters to really push the air through the system. Without that the gfx card and case can get really hot. I have the RTX 2080 and that bad boy can cook. 
    1. At the bottom of the case is a removable mesh screen. It is right next to the power supply. When I saw that I was like OMG, great place for a fan...why didn't they put a fan mount here! It is a great place for a fan and the mesh works as a decent filter. It is ideal to pull air from the bottom (cooler) and eject it from the top (hotter).
    2. There is a SATA power connector on the small bottom (bottom right of the case) circuit board. Get a splitter and install a fan sitting on the wire mesh. Use it as an intake, get a good RPM fan so the air prefers this intake. This should help the system stay neutral pressure and avoid air coming in from the cracks.  
    3. Installing the fan will help push air through the system and provide more cool air to the gfx card. If you take this approach get something to lift your computer. The existing rubber feet do not provide enough clearance for ideal air flow. I just cut some wood to make feet, works well. I need to paint the wood black at some point. 

Here is a picture of the finished build. I am sure there are ways to improve it. I do need to cable manage a bit better at the bottom, but for now, it is pretty hard to get good. Look forward to hearing and seeing what others have done. 

Finished PICFinished PICFinished PIC with notesFinished PIC with notes

*The DIY Lifts text moved on me. Should have been on the cool wooden feet I made at the bottom of the pic. 


H60 Review

My stock case had the CPU and GFX card running at 50C idle. The cooling on the Obelisk isn't great...but that is within a good range for both components. I play a lot of games and Overwatch heats up my system the most. I was routinely getting temp alerts when playing Overwatch and VR, my threshold was set at 80C. It is the reason I looked into liquid cooling. Since I put in the unit my temps are 35C idle. My CPU temps barely break 50C now under load. My gfx card still gets hot but rarely breaks 70C. I can get it up to 80C with a long VR session, but it can handle up to 88C. 


The biggest benefit to liquid cooling the CPU is to get the CPU heat up and out of the case. This helps cool your gfx card and overcome some of the airflow challenges with the case. In all, I am happy with the H60 and would probably have purchased again if I did it over. I like the unit and love the white LED glow. It is a good contract to the case's LED colored lighting. Plus it is a great price. 


In terms of noise, the system is quiet. Much quieter than when the CPU fan was on it. I do not have any complaints in the noise area, but my house is a bit noisy itself. So others might have another take on it. 


I will try and be active on the post with any replies. However, I don't visit the boards much and this is my first HP product outside of a printer. I have notifications set on replies and I will try to be as active as possible. If HP wants to send me products to review and write up on maybe I will be more active 🙂


Reference Links





The splitter I used: https://www.amazon.com/gp/product/B01IBA3XCW/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1


The SATA to 4-Pin converter I used, for the bottom fan: https://www.amazon.com/gp/product/B072JGSV6D/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1


Temp Pic - at idle


HP Recommended

This post is absolutely helpful!


How did you mount the intake fan at the bottom? Would you mind taking close-up pictures of the intake fan and how it is powered?


Why did you not connect the cooler pump 4-pin header to the LC_PUMP header on the mobo (the one near the top of the mobo)?


I know that HP have this rigged so it controls the fan speeds automatically; does that include the exhaust fan speed at the back (via PWM or Voltage control?)? If so, is it a good idea to use splitter (link below) on the SYS_FAN connector of the mobo to control both the intake and exhaust fan speeds?




Would you know what are the voltage and amperage ratings for the SYS_FAN connector? What are the voltage and amperage ratings for the stock fan? 



HP Recommended

Thanks, for the feedback. 


--For now, I haven't mounted the bottom intake fan. It is resting on the mesh plate. I am looking into options on how to mount it. However, it is stable and doesn't require mounting. I am thinking of making custom brackets on the removable mesh piece itself. 


--I did forget to mention the fan and pump connections, great catch. The fan is connected to the CPU FAN 4-Pin. The Pump is connected to the PUMP 4-PIN. The H60 requires a SATA power connection in addition both the 4-PIN connections. Not sure why some speculate it is because of the LED lighting, others say the pump is designed to operate at max all the time. Other pumps do not require a SATA power source, the H60 (2018) does. 


--The splitter for the intake is a great idea. That would match the speeds of the other fans. The only outlier is the gfx card. If you have a newer model, in this case, it gets hot. It would be preferable to have the intake at max speed for the gfx card, even when the CPU doesn't require it. Part of my idea to get a strong intake fan is to create a neutral or positive pressure in the case. That way the air comes mostly from the bottom, passing through the mesh and getting filtered a bit. Having the gfx fan regular outtake fan and the radiator fan creates a good balance with an always-on strong intake at the bottom, or should in theory. 


--I am not sure of the voltage rating, I will review my rig and see if I can find it and post back. 

HP Recommended

Which screws did you use to mount the cooler on the bottom of the bracket?

HP Recommended

Hi Swiftburn,


Nice job. Kudos! :ThumbUp:


You picked a good AIO for your PC's motherboard.


I noticed the H60 does not have a USB 2.0 connection to the MB. So I am guessing you are not using and are not able to use Corsair Link software to control the fan speed and pump speed. You have CAM installed but CAM cannot monitor or modify Corsair H60 CPU fan and pump parameters.


You are letting HP's BIOS control this. How are the sound levels and fan speeds? HP does not usually allow customized fan and pump mods in the BIOS.


I don't believe the Obelisk 875 series MB has open USB 2.0 fan headers.


I have installed Corsair H80i AIOs, H100i AIOs, NZXT Krakens, and other retail AIOs on retail MBs which require an open USB 2.0 header on the MB.


Again, nice work.





HP Recommended

Hi just got the same cooler I have a quick question there are three wires to plug in is it ok to just plug in the 3 pin and 4 pin is is the other cable have to be plugged in I’ve got 2 days to find out as my thermal paste order got delayed 


thanks and nice job

HP Recommended

Would the Corsair H60 120mm work with the Omen Hp 875-0XXX? I can’t seem to find any actual legit info on this. Thanks.

HP Recommended

So I'm considering upgrading some cooling myself, but I'm more likely to go in the direction of the graphics card. Water cooling the CPU seems to be slightly less bang for the buck considering the 8700 cant be overclocked. The video card on the other hand has a very serious heating issue. To reach it's formidable potential the video card is gonna need a much better cooling system then the stock fan system built into it. Just my opinion, but those are my thoughts.

HP Recommended

I watched some YouTube videos, there’s a guy who shows some upgrades he did to his PC. He ended up changing the chasis, I didn’t go that far. I managed to change few things and space inside. I never thought about the splitters, got a whole PSU instead.



HP Recommended

Hello i would like installed a fan on the bottom of the PC but i do not know or plug my SATA sockets on the small circuit board SATA socket  is already used on this one i do not see or plug it I would like to have a bit of help plz

Techko tek how do you connect the port to USB NZXT in pc because to my knowledge there is no USB port on the motherboard


† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the <a href="https://www8.hp.com/us/en/terms-of-use.html" class="udrlinesmall">Terms of Use</a> and <a href="/t5/custom/page/page-id/hp.rulespage" class="udrlinesmall"> Rules of Participation</a>.