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    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooling I Intel LGA 1851 / 1700 / 1200 / 1150 / 1151 / 1155 I AMD Socket AM5 / AM4 / TR5 / TR4 - BW026

    • 3 Fan Slots (140mm)
    • 2 Fan Slots (120mm)
    • 3 Fan Slots (120mm)
    • Silent Loop 3 420mm is the virtually inaudible and incredibly high performing All-in-One water cooling unit with state-of-the-art technology. Silent Loop 3 is the epitome of a German engineered piece of hardware that embodies what be quiet! is associated with.
    • Highly engineered cooling block design
    • Powerful 3-chamber pump design significantly reduces turbulences and noise
    • Dampened and adjustable pump with 6-pole motor
    • 3 Silent Wings 4 140mm PWM high-speed fans with radiator corners for virtually inaudible operation
    • Incredibly high cooling performance
    • Elegant premium design with discreet ARGB lighting
    • Easy-to-access refill port and included coolant bottle for a long lifespan
    • Flexible sleeved tubes and a convenient mounting ensure easy handling
    • 3-year manufacturer’s warranty
    • Product conception, design and quality control in Germany
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    Overview
    Specs
    Reviews (32)
    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler
    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    SILENT LOOP 3

    420mm

    Superior technology and cooling

    Silent Loop 3 420mm is the virtually inaudible and incredibly high performing All-in-One water cooling unit with state-of-the-art technology.

    • Highly engineered cooling block design
    • Powerful 3-chamber pump design significantly reduces turbulences and noise
    • Dampened and adjustable pump with 6-pole motor
    • 3 Silent Wings 4 140mm PWM high-speed fans with radiator corners for virtually inaudible operation
    • Incredibly high cooling performance
    • Elegant premium design with discreet ARGB lighting
    • Easy-to-access refill port and included coolant bottle for a long lifespan
    • Flexible sleeved tubes and a convenient mounting ensure easy handling
    • 3-year manufacturer’s warranty
    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    Silent Loop 3 420mm is ready for modern flagship CPUs like Intel's Core i9 or AMD's Ryzen 9 series, with room for overclocking.

    WHAT A COOL(ING) BLOCK

    Obsession with details

    The cooling block of Silent Loop 3 420mm is undisputed. The explanation may look complicated, but we owe it to our most loyal fans and all the enthusiasts out there: The cooling block boasts a 1,800 mm² fin area, which is an increase of up to 2x compared to many other AiO's in this class. This greatly improves heat transfer and makes sure to cover all hot spots on the CPU. The large fin area could only be achieved by a specially developed screwless design for attaching the heat plate. The internal design of the flow path takes care that all areas are flowed to evenly to achieve high performance regardless of the CPU platform.

    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    SUPERIOR PUMP DESIGN

    Enjoy the silence

    A powerful PWM pump with 3-chamber design ensures the very high-performance of Silent Loop 3 420mm and is whisper-quiet at the same time. The second of its 3 chambers acts as a reservoir and offers enough space for the coolant to spread out and thus reduces turbulences before the liquid leaves the pump unit. In combination with the 6-pole 3-phase motor this results in a smooth and consequently silent operation.

    SILENT WINGS 4 FANS

    Virtually inaudible operation - period

    Silent Loop 3 420mm features 3 Silent Wings 4 140mm PWM high-speed fans. These fans feature silence-optimized fan blades and a funnel shaped air outlet, making Silent Wings 4 140mm PWM high-speed a fan that makes no compromises between very quiet operation and highest performance. The corners of the frame are designed to minimize air leakage on radiators.

    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    INCREDIBLY HIGH COOLING PERFORMANCE

    Be ready for any setup

    Silent Loop 3 420mm is a meticulously crafted masterpiece of German engineering. All parts integrated are of highest quality and work as precise as a clockwork, ultimately leading to a cooling performance ready for virtually any situation.

    EASY TO REFILL

    Simplified refilling process for a long lifespan

    An easy-to-access refill port makes for convenient handling, safe refilling and comfortable maintenance. The coolant bottle included extends the lifespan.

    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler
    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    S-TIER DESIGN

    The perfect mix between power and elegance

    The cooling block’s design is iconic and unmistakable. We kept it all-black and elegant to represent the sheer cooling power Silent Loop 3 420mm offers, despite being barely audible. Optionally, you can turn on ARGB LEDs. Silent Loop 3 420mm is a statement in your PC case: you strive for the maximum in any discipline.

    "I am an engineer with heart and soul, which is why I had so much fun making the Silent Loop 3 the technical masterpiece that it is. I recommend Silent Loop 3 even to my closest friends. That should say it all."

    Tim Carstensen, R&D Department BU Cooling

    be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler be quiet! SILENT LOOP 3 420mm All-in-One Water Cooler

    Warranty & Returns

    Warranty, Returns, And Additional Information

    Warranty

    • Limited Warranty period (parts): 3 years
    • Limited Warranty period (labor): 3 years
    • Read full details

    Return Policies

      We want to ensure your holiday shopping this year is hassle-free. That’s why we’re automatically extending our return policies on almost every product! For purchases placed between November 1st, 2026 and December 31, 2026 you will have until January 31, 2027 to return your product.

    • Return for refund until: January 31, 2027
    • Return for replacement until: January 31, 2027
    • This item is covered by Newegg.ca's Extended Holiday Return Policy.
    • Read full return policy for details.
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    The be quiet! SILENT LOOP 3 420mm is a high-performance all-in-one liquid CPU cooler with a 420mm radiator, three 140mm PWM fans, and a noise-reducing three-chamber pump, suited to enthusiasts building powerful systems who want strong cooling with quiet-focused operation.

    Recommended For

    • People running sustained, high-heat CPU workloads—such as long renders, code builds, or CPU-heavy content creation—who have room for a 420mm radiator; reviews report strong cooling performance under heavy loads.
    • Builders creating a quiet-focused desktop for demanding work or gaming who want strong cooling without relying on maximum fan speeds; reviews found low noise relative to competing coolers.
    • AMD Threadripper workstation builders who need a compatible AIO and can accommodate its large radiator and CPU block; the cooler supports TR4 and TR5 sockets.
    • PC builders who prefer a serviceable AIO and plan to maintain it over time; it has an accessible refill port and includes extra coolant.

    Spec Summary

    AttributeValue
    Best ForIntel or AMD systems using a listed socket that need an all-in-one liquid cooler with a 420 mm-class radiator and three 140 mm fans
    Cooling ConfigurationWater-based all-in-one liquid cooling system
    Socket CompatibilityIntel LGA 1150, 1151, 1155, 1200, 1700, and 1851; AMD AM4, AM5, sTR4, and sTR5
    Pump And Cooling BlockAdjustable pump speed of 1,700–3,500 RPM; cooling block measures 93.5 × 80 × 56 mm
    Radiator And Tubing457 × 140 × 27 mm aluminum radiator; 400 mm tubes; 100 ml coolant capacity
    Fans And AirflowThree 140 × 140 × 25 mm fans with FDB bearings, 1,900 RPM maximum fan speed, 78.4 CFM (133.2 m³/h) airflow, and 2.36 mmH₂O pressure at 100% PWM and 12 V; 4-pin PWM connection
    Power And NoiseRated at 3.6 W and 12 V; listed noise level of 34.3 dB
    Materials, Appearance And WeightAluminum and copper construction with an aluminum radiator; black finish, listed as non-LED; item weight 2,010 g
    Model Identifiersbe quiet! SILENT LOOP 3 420mm, part number BW026