# Tandem T:slim app won't connect **URL:** \ **Category:** Pump\ **Tags:** tandem-x2\ **Created:** [April 27, 2025, 6:16pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249 "2025-04-27T18:16:05Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![CarlosLuis](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/carlosluis/32/11389_2.png) [@CarlosLuis](https://forum.fudiabetes.org/u/CarlosLuis)\ **Post date:** [April 27, 2025, 6:16pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/1 "2025-04-27T18:16:05Z")
I used the app to do a correction bolus ok. 30 minutes later the app lost connection with the pump. It asks for paring code I put it in, but no good. The pump and Dexcom app are working just the Tandem app that’s not. I rebooted my iPhone. I’ll be changing sensor later, maybe that will clear this up. ---
**Author:** ![D1958](https://avatars.discourse-cdn.com/v4/letter/d/bbce88/32.png) [@D1958](https://forum.fudiabetes.org/u/D1958)\ **Post date:** [April 27, 2025, 11:15pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/2 "2025-04-27T23:15:15Z")
Have you checked if the phone still has a bluetooth connection with the pump? ---
**Author:** ![CarlosLuis](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/carlosluis/32/11389_2.png) [@CarlosLuis](https://forum.fudiabetes.org/u/CarlosLuis)\ **Post date:** [April 28, 2025, 12:01am UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/3 "2025-04-28T00:01:07Z")
Yes it’d show disconnected will connect and disconnects after 10-15 seconds. ---
**Author:** ![elver](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/elver/32/8772_2.png) [@elver](https://forum.fudiabetes.org/u/elver)\ **Post date:** [April 28, 2025, 5:40am UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/4 "2025-04-28T05:40:38Z")
@CarlosLuis FWIW here’s a link to Tandem’s troubleshooting page on that issue. Maybe there will be something useful there. > **[Connection Errors on the Tandem t:slim Mobile App](https://www.tandemdiabetes.com/support-center/software-and-apps/tandem-tslim-mobile-app/article/connection-errors-on-tslim-app#connection)** > > If you see any of these error messages on your mobile app, you can attempt to resolve the issue on your own by completing each of the steps here. ---
**Author:** ![CarlosLuis](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/carlosluis/32/11389_2.png) [@CarlosLuis](https://forum.fudiabetes.org/u/CarlosLuis)\ **Post date:** [April 28, 2025, 3:34pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/5 "2025-04-28T15:34:37Z")
For any Tandem X2 users who runs into this problem. Changing the sensor did not fix it. Called Tandem support and got Alex. The pairing code is not the same as the sensor paring code. Here’s the steps to get the code for pairing pump to app. Unlock\>Options\>Device Settings\>Bluetooth Settings\>Unpair Device\> Pair Device (get code, mine was 6 digits) Open app click the bubble to verifiy the pump serial number\>enter the pairing code, wait while the circle spins around. If successful the dashboard should come up and after a bit will show connection to the pump. I did not find anywhere that there was a separate pairing code for the app and for the sensor. Hopefully the unexpected loss of pairing between pump and app won’t happen to anyone here. ---
**Author:** ![mremmers](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/mremmers/32/1300_2.png) [@mremmers](https://forum.fudiabetes.org/u/mremmers)\ **Post date:** [April 28, 2025, 7:37pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/6 "2025-04-28T19:37:12Z")
I had this same issue come up a few days ago. I tried everything and finally just deleted the app, rebooted, then reinstalled the app and all was well. No data was lost. Glad you found a solution, @CarlosLuis. ---
**Author:** ![jim26](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/jim26/32/9780_2.png) [@jim26](https://forum.fudiabetes.org/u/jim26)\ **Post date:** [April 29, 2025, 12:54am UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/7 "2025-04-29T00:54:06Z")
I use Android and have this issue a lot since I did the recent Tandem update. Turning off bluetooth and turning it back on resolves the issue, but it is annoying. ---
**Author:** ![cogdog](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/cogdog/32/5436_2.png) [@cogdog](https://forum.fudiabetes.org/u/cogdog)\ **Post date:** [May 10, 2025, 2:23pm UTC](https://forum.fudiabetes.org/t/tandem-t-slim-app-wont-connect/15249/8 "2025-05-10T14:23:49Z")
I’ve been on T:slim since January and never knew there was an iPhone app. Curiously the app seems to be not available here in Canada? Had a slightly different issue recently. The Dexcom app worked fine but the t:slim pump blared an alarm that it could not connect to the sensor. Found from searches that the pump in my left pocket can lose connection from a sensor on right side of stomach. Yep, moving the pump closer snapped it to life. I guess time to do more sit-ups? 😉