What should I do if I see air bubbles in my tubing? (t:slim X2 insulin pump)

While air bubbles themselves will not harm you, there could be a risk of high blood sugar if air is infused in place of insulin, causing missed insulin delivery. Small or champagne sized bubbles are not a concern. If you are seeing large bubbles or gaps, please proceed to the troubleshooting steps below.

Troubleshooting Steps:

  1. During normal pump use, ensure that you do not disconnect from the t:lock connector (number 1 in image below), as doing so may introduce air into the tubing. If you need to disconnect your infusion set, please do so from the site on your body (number 2 in image below).


  1. Check to ensure that the t:lock connector is straight and tightened securely to your infusion set tubing.



  1. If you see large air bubbles or gaps, orient the cartridge and tubing upwards to allow any bubbles to move toward the top.


  1. Ensure that your infusion set tubing is disconnected from the site on your body, then navigate to Options > Load > Fill Tubing on your pump screen. When prompted, select FILL and prime your tubing until the large air bubbles/gaps are gone.


  1. If large air bubbles or gaps still exist after priming the tubing, load a new cartridge onto your pump using proper load technique.

If you are still seeing large air bubbles after completing these steps, please contact Customer Technical Support.

To help avoid this in the future, make sure you are following the on-screen load instructions and using proper load technique.

Load Sequence Tips (t:slim X2 insulin pump):

  • Do not re-use or re-fill cartridges.
  • Use the syringe that came with your cartridges.
  • Use room-temperature insulin.
  • Ensure there are no visible cracks in the cartridge.
  • Ensure that there are no visible air bubbles in the syringe.
  • We recommend filling the syringe with a minimum of 120 units.
  • Only used approved insulins.
  • Ensure you insert the needle in the center of the white cartridge fill port.
  • Do not overfill cartridges. The base of the syringe’s plunger should not pass the 3mL line.



  • Ensure you remove the residual air from the cartridge before filling.




Click here for step-by-step instructions on filling and loading a cartridge: How do I load a cartridge on my t:slim, t:slim G4, t:slim X2, or t:flex insulin pump?


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