New Tandem tech problem?

I have not seen this before nor has my Endo. Three times in 28 hrs my T:slim X2 pump has shown 0 insulin in the cartridge hours after I had filled it. I called Tandem at time 2 and they said x3 would result in a new pump which occurred this morning. So a new pump is on the way. I was goofy enough to fill the cartridge the 2nd time so I have lost a lot of insulin. I have plenty though.
As noted, I have not seen this particular issue online. My Endo, who I saw this morning right after it happened the 3rd time in his parking lot, said he had not heard of it.
I learned you can’t trick it into taking the same cartridge after removing it either. It was almost full but it knew it was the same one and refused it.

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You can draw insulin out of the cartridge with the 3 cc syringe.

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I tried that but so far was unable to. Will try again then.


That’s particularly baffling. I’ve pulled out a cartridge, gone through the whole loading process and snapped back in the same cartridge a few times for various reasons and never had a problem. Why would they develop and implement individual cartridge identifying tech?
Did you go through the whole loading process and it rejected the cartridge? I’m wondering if instead of having a faulty pump you have faulty cartridges and that’s why the cartridge was rejected when you tried to load it a second time — not because it somehow knew you were reloading the same cartridge.
Have you used cartridges from different boxes?


The cartridges I used were from the same box. Tandem got the lot number from me. But I think it is the pump but who knows. If there is space, I will return one of the cartridges with the pump. I also had to keep adding insulin to the last one. I know I had 50 u in but it kept saying I didn’t. I didn’t want to enter another full cartridge. I think this pump has just gone bad. I get the “new” pump late tomorrow. I have Lantus or some type of longacting insulin waiting at drugstore just in case. The next pump will allow both g6 and g7 Dex as this one had not yet been upgraded. I told him I was not going with g7 yet!

Checking on something else. CAn anyone tell me if the Tandem pump will connect with Clarity online with its cable?
I was just sent to Tandem by Dex because they said if it was on the pump they could not help me. I wanted to get a month of readings off before switching to my new pump. And nope, I had not tried it before.

Twice now Dexcom tells me that I can’t upload Dex readings from the pump into Clarity online. And yet they do allow Dex to reside in the pump. She said I had to have a sensor or have it in a smart phone to upload the readings. Interesting.

Another point. Why is my new pump getting extended years? Meaning it now goes to 1929 instead of 1927. I thought you got a repaired pump and kept your same warranty date as with the previous one. If you get a brand new pump I guess a new warranty start would make sense. Medtronic replacements were repaired ones. This is quite an experience.

The Tandem phone app or t:connect uploader sends the data to Tandem. You can get a report from the app or using the Tandem Source web portal.

Yes, the tandem person showed me that. It doesn’t have as many analyses though. Thanks. If I could or can get the raw data, then I
could do my own analyses.

I have removed, refilled, and reused cartridges MANY times! New infuser and tubing, same cartridge! The cartridge has no sensor itself, it’s just a dumb reservoir with a couple mechanical connectors.
I don’t go beyond one extension of use, though. So: total of a week or 8 days.
I’d bet the problem you’re seeing is pump related.
Not that I’m recommending anyone reuse cartridges, but it’s been no issue in my life.


Yes, I think it was my pump. I finally got on my new pump last night. Hooray! I have been thinking my other pump was “not right” for several months now. But the last couple of days one of the Tandem people let the word “motor” drop and I think it was either a bad motor or whatever senses what goes on with the cartridge was bad.
One thing that hit me as I was transferring data was that before Tandem my TDD was about 55 and now it’s about 45 or less. Tandem person insisted I enter 55 “because that’s what your health care provider entered” which is not true, but of course I did not enter 55. I looked at my history on the old pump beforehand and it was 35 to 45 a day. Before CIQ it was much higher. Not to mention losing a few pounds!
Thanks Folks.

Good Morning Blueburd:

On occasion, I’ve refilled my old cartridges, when supplies were running low. With the possible exception of one or two that were accidentally overfilled and failed.

It can be done, on an as-needed basis.

Your mileage may vary… :syringe:

Good luck


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I’m pretty sure you meant 2029 and 2027.:smirk:

I had this same problem two years ago. I would do everything normally to insert a new infusion site with a filled cartridge and shortly afterwards I would get a low insulin alarm and the pump would show that I had 10 units left. After the second time this happened I received a replacement pump from Tandem. I have not seen this issue with the new pump. Obviously this is a rare T2 pump failure…


I’m glad to hear that at least one other person has had this problem but not glad it happened. I knew I had never heard of it. I am so glad my new pump is working well. And best of all the new software allows me to stop insulin for 30 minutes without driving me nuts with frequent loud beeps that it is stopped!! I had two lows today and it came in handy both times (it can take juice a while to work for me and I was at PT and it was what I had). Anyway, that feature I appreciate. But if you had this problem 2 years ago, I don’t know why it is still happening.