Installing an all-in-one (AIO) liquid CPU cooler involves mounting the radiator in your case with fans oriented for proper airflow, securing the pump block onto the CPU with thermal paste using the included bracket, then connecting the pump’s cable to the motherboard and the radiator fans to their respective headers.
- Plan radiator placement and fan orientation before starting installation.
- The pump block mounts to the CPU almost identically to an air cooler.
- Connect the pump cable to the CPU_FAN header, not a case fan header.
- Bleed any air bubbles by briefly running the pump before final case closure.
Step 1: Plan Radiator Placement
Most cases support radiator mounting at the top or front. Top-mounted radiators typically work as exhaust, while front-mounted radiators usually work as intake, pulling cooler outside air across the radiator before it reaches the fans. Confirm your case supports your specific radiator size, following the general form factor considerations in motherboard form factor for overall case compatibility.
Step 2: Mount the Radiator and Fans
- Attach the fans to the radiator first, checking the airflow direction arrows printed on the fan housing.
- Mount the radiator-and-fan assembly to the case using the provided screws, in your planned location.
- Leave cables loosely connected until final routing, to make handling the assembly easier during mounting.
Step 3: Install the CPU Backplate and Bracket
Most AIO coolers use a backplate and mounting bracket similar to air coolers, following the general approach in how to install a CPU cooler. Confirm you’re using the correct bracket for your specific CPU socket, since brackets often differ between Intel and AMD platforms.
Step 4: Apply Thermal Paste and Mount the Pump Block
Apply a pea-sized dot of thermal paste to the center of the CPU, then lower the pump block into place, tightening the mounting screws in a diagonal pattern for even pressure, similar to the process for repasting a CPU.
Step 5: Connect Cables
- Connect the pump’s cable to the motherboard’s CPU_FAN header, not a standard case fan header, since some motherboards monitor this specifically for CPU temperature safety shutoffs
- Connect radiator fan cables to available fan headers, using a fan hub or splitter if your motherboard has too few headers
- Connect any RGB or lighting cables if your specific AIO includes them
Step 6: Power On and Check for Proper Operation
Before closing the case, power on briefly to confirm the pump is running (you should feel slight vibration or hear a faint hum) and fans are spinning. This also helps circulate the coolant and settle any small air bubbles introduced during manufacturing.
Warning: never run the system for extended periods with the pump disconnected, even briefly, since this can allow the CPU to overheat within seconds under load with no active cooling.
See also installation tips from Gamers Nexus, safety guidance from iFixit, and community build photos on r/buildapc.
Frequently Asked Questions
Where should the pump cable connect on the motherboard?
The CPU_FAN header specifically, not a standard system or case fan header, since some boards use this for safety monitoring.
Does radiator orientation matter?
Yes, top-mounted radiators typically work as exhaust while front-mounted ones usually work as intake, affecting overall case airflow.
Do I need to bleed air from an AIO cooler?
Most closed-loop AIOs are sealed and don’t require manual bleeding, though briefly running the pump helps settle any minor air bubbles from manufacturing.
Can I use the same bracket for Intel and AMD?
No, confirm you’re using the correct bracket for your specific CPU socket, since AIO coolers typically include separate brackets for each platform.
