The Ultimate Guide: What Size Torque Wrench for Daikin Mini Split

When it comes to installing a Daikin mini-split system, ensuring the proper tightening of the refrigerant pipe joints is crucial for the system’s efficient and safe operation. The installation manual provided by Daikin specifies the required torque values for these connections, and using the right size torque wrench is essential to achieve the recommended settings.

Understanding Torque Requirements for Daikin Mini-Split Systems

According to the Daikin installation manual, the refrigerant pipe joints should be tightened with a torque wrench at the following specifications:

Gas Side Flare Nut Tightening Torque

  • 5/8 inch (15.9mm) pipe: 45-5/8 to 55-5/8 lbf•ft (61.8 to 75.4 N•m)
  • 1/4 inch (6.4mm) pipe: 10-1/2 to 12-3/4 lbf•ft (14.2 to 17.2 N•m)

Liquid Side Flare Nut Tightening Torque

  • 1-3/16 inch (30mm) pipe: 8-10-7/8 lbf•ft (10.7 to 14.7 N•m)
  • 11/16 inch (17mm) pipe: 16-5/8 to 20-1/4 lbf•ft (11/16 inch (17mm)) for a 10-1/2 to 12-5/8 lbf•ft (14.2 to 17.2 N•m) pipe

Selecting the Appropriate Torque Wrench

what size torque wrench for daikin mini splitImage source: Flickr

Based on the torque requirements specified in the Daikin installation manual, a torque wrench with a range of 10-70 lbf•ft (14-95 N•m) would be sufficient for tightening the refrigerant pipe joints of a Daikin mini-split system.

Torque Wrench Size

The size of the torque wrench depends on the size of the flare nuts used in the Daikin mini-split system. According to the manual, the gas side flare nut is 5/8 inch (15.9mm), and the liquid side flare nut is 1-3/16 inch (30mm). Therefore, a 1/2 inch drive torque wrench with a socket size of 5/8 inch (15.9mm) or 1-3/16 inch (30mm) would be appropriate.

Torque Wrench Brands

There are several reputable brands of torque wrenches available on the market, such as Snap-on, Craftsman, and Proto. When selecting a torque wrench, it is recommended to choose a brand with a good reputation for accuracy and durability.

Proper Torque Wrench Usage Techniques

To ensure accurate and consistent tightening of the refrigerant pipe joints, it is essential to follow proper torque wrench usage techniques:

  1. Calibration: Regularly calibrate the torque wrench to ensure it is providing accurate readings. Refer to the manufacturer’s instructions for the recommended calibration schedule.

  2. Slow and Steady: Apply the torque slowly and steadily, without jerking or sudden movements. This will help prevent damage to the flare nuts and ensure the proper torque is applied.

  3. Proper Positioning: Hold the torque wrench perpendicular to the flare nut, with the handle positioned at a 90-degree angle to the nut. This will ensure the torque is applied correctly.

  4. Tightening Sequence: Follow the recommended tightening sequence specified in the Daikin installation manual to ensure even distribution of the torque across all the refrigerant pipe joints.

  5. Double-Check: After tightening the flare nuts, double-check the torque values to ensure they are within the specified range.

Troubleshooting and Maintenance

If you encounter any issues with the refrigerant pipe joints, such as leaks or improper tightening, refer to the Daikin installation manual for troubleshooting guidance. Additionally, regularly inspect the refrigerant pipe joints and retighten them as necessary to maintain the system’s optimal performance.


Selecting the right size torque wrench and following proper usage techniques is crucial for ensuring the proper tightening of the refrigerant pipe joints in a Daikin mini-split system. By adhering to the manufacturer’s recommendations and using the appropriate tools, you can ensure the safe and efficient operation of your Daikin mini-split system.