High Altitude Alarm

Has anyone else run into this alarm on the t:slim?

I received it not after a flight, but rather after a hot day of bike riding. I wear my t:slim against my hip when I ride and I have been doing this for 6 months. But this past weekend after coming home and changing the infusion set and cartridge I received a High Altitude Alarm - All Deliveries stopped.

I called Tandem and they told me that there are 6 tiny holes in the back of the t:slim and in some cases if they get clogged the t:slim thinks you're in a high altitude and stops delivering basal insulin.

The t:slim said to remove the cartridge and put it back in. I did that a few times and it seemed to fix itself.

Am I the only one who sometimes wears the t:slim again the skin?


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I do all the time but because of the vents I always place it with vent holes away from body. You can help decrease the sweat build up on the screen by placing it in a baby sock if you are having direct skin contact.
But the pump is water resistant so the sweaty scene will not cause issues. I wear mine in a talleytote all the time, so is held close to body. Can get totally soaked with day hiking in the mountains during the summer.

Tandem also recommended the baby sock solution - but that kinda defeats the "slim" aspect of the design, which was a buying point for me. They also did not recommend the screen facing the skin, but that is only because they don't want you to accidently dose. But I think that would be very difficult to accomplish with the locks and confirmation screen necessary to bolus.

You are right though, if the device is water resistant then sweat should be no problem either. Thanks!

What's a talleytote? Can you give a link to the product? Thanks.


I'm using the tummietote 2 with 1 clear window for my Dex receiver, I use one of the pockets on the band for pump, another for ID, keys and there are enough to carry a few carbs of choice. I can put a few GU gels in as well as a roll of smarties as well.

I tried the tslim through the window and while it will work it tends not to be centered so is difficult to do. I tend to use the rapid bolus mode slot so for me it's not an issue.

Hi everyone :)

I use a short length 23" tubing set with my T-Slim and I wear it around my waist.
Never had a problem with it getting sweaty or dirty. I use a runners belt. Very comfortable and durable as well. Machine washable and everything keeps a low profile even under t-shirts.
I picked mine up at Amazon and I would highly recommend it. Here is a link:

Hope this helps someone. All the best,
- Mario


Reviving this from the dead because I just had this alarm. I’ve worked out before with the X2 pump as it’s May and I’ve been wearing the pump since mid-January. I am increasing the intensity of my workouts, but I don’t wear the pump against me. I usually have it up on my sports bra strap on attached to the machine I’m using. Where it does get moisture is in the shower. I shower with it on because after that I go into the steam sauna. I take it off in the sauna and put it back on after that. I take a LONG time in the locker/room shower, so it would be a good 30 minutes of me being disconnected vs. maybe 5-10, which is about how long I’m in the steam sauna.

After the gym, I ran some errands grabbed a snack and finally got home. THEN I get the altitude alarm. I follow the instructions: remove the cartridge, which does nothing, and called Tandem. I then took it out of its case and wiped it down. Nothing…

On a Saturday afternoon, the wait was close to one hour. (Yes, I know I can do the automated call back thing, but I tried that; I was moving around at the time and forgot to mute my phone, so after I entered my number, I didn’t get (or hear) a confirmation.) I called back because my pump on strike.

When I get through the rep was great. He told me to take it out of its case, which I’d already done. Told me to wipe the 6 small dots down with a Q-tip and alcohol and to carefully put a pin into the holes to clean it out. It looked clean to me, so I was cynical. However, sure enough, that did the trick. I’m just glad I know that this is possible. I’ll be a little bit more careful in the gym during my shower/sauna time.


The only time I have ever gotten this is after a shower. I clip the pump to a chain around my neck. It seems like ever since I started using the G6 and added Basal-IQ, it happens much less frequently. I would dry it off as thoroughly as possible, including the cartridge slot and every nook in the cartridge. But it would give me the alarm until I’d dried it 2-3 times. Then on a whim, I tried drying it with a hair dryer. I’d pull the cartridge and blow dry the slot, and very quickly, the cartridge. It works every time.

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when I got this alarm my husband sprayed the little vent holes with compressed air (like for cleaning keyboard) and it came right back to life!

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I jam my pump into my sports bra during workouts so obviously it has happened more than a few times. It fixes itself pretty quickly