Tandem Occlusion Alarms: The Last Post

I started using a Tandem t:slim X2 insulin pump in December 2016 and immediately began having occlusion alarms once or twice a week. I had never had occlusions in 12+ years of pumping with Medtronic and Animas and quickly discovered that the vast majority of these Tandem alarms were false. All I had to do was dismiss the alarm, resume insulin, and go about my day. I can count on one hand the number of times that the occlusions were real and required a cartridge and infusion set change. It takes more than one hand to count the times that I had an embarrassing blaring alarm in awkward situations such as the movies, yoga class, and restaurants.

If you do an online search for Tandem Occlusion Alarms, you will be linked to some of my older blogposts. People still contact me with questions about their occlusion problems and I figured it was time to update my experiences and thoughts.

Although some of my previous blogposts suggested that I had fixed the problem, I never found a permanent solution to false occlusion alarms with some of my X2 pumps. I was fortunate that I wasn’t someone who had multiple alarms a day requiring cartridge and infusion set changes. The alarms were annoying and I mostly learned to live with them. Occasionally I called Tandem out of frustration but after a while they had nothing new to tell me and no real solutions.

If you notice in the last paragraph I say “some of my X2 pumps.” I am on my fifth pump in 3-1/2 years. My first pump had occlusion alarms starting the first week and was eventually replaced due to a failed battery. The second pump did not have a single occlusion alarm during the month that I used it, but the t:button was defective. The third pump had lots of occlusion alarms and was replaced for that reason. The fourth pump had one to two occlusion alarms per week and I gave up on solving the problem. 

But then….

In January 2020 I started using Dexcom G6 and wanted to install the newest Basal IQ update. It was determined that I had one of the older pumps with software that was incompatible with the Basal IQ and Control IQ updates. So I got another replacement pump. Amazingly several months went by with no occlusion alarms. I didn’t change anything in my behavior, cartridge use, or infusion set type. Through luck of the draw I finally had a pump that was not prone to false occlusion alarms. In the last 6+ months I have had 3 occlusion alarms all probably attributable to bunched up tubing during a mealtime bolus. 

I have long believed that some Tandem pumps are more prone to occlusion alarms than others. Is it an overly sensitive sensor or a less than robust motor? I’m not an engineer and have no idea. I have more than once been annoyed by people online being virtuous that they aren’t getting occlusion alarms and that I must be doing something wrong. Some times I felt as though Tandem techs blamed me.

No, maybe it was just the pump.

If you’re dealing with occlusion alarms, the best place to start might be with some of the “best practices” recommended by Tandem support techs and other X2 users on Facebook. Some helped me, some didn’t, and some I refused to do.

Things to try:

  1. Use the case
  2. Don’t carry the pump in your pocket
  3. Keep the tubing outstretched while a bolus is delivering
  4. Change your cartridge every 3 days
  5. Use TruSteel infusion sets
  6. Use insulin types approved for Tandem pumps
  7. Document everything and work with your local rep to get a replacement pump
  8. Just accept occlusion alarms, restart insulin, and move on

I don’t necessarily do all of those things and some of them made no difference in the number of my occlusion alarms. With only one to two alarms a week, I got very good at #8 and just lived with the alarms. I currently wear my pump on my waistband with a Nite Ize clip and use TruSteel infusion sets with Novolog insulin. But that’s what I did with the 3rd and 4th pumps that had lots of occlusion alarms. I dislike the size and weight of the case and don’t use it. I don’t change my cartridge every three days although I change my infusion set every two days. I rarely hold the tubing straight during a bolus.

So I live with a mixture of best practices and bad practices. I used to get a lot of occlusion alarms and now I don’t.

What changed?

The pump.


I hope that this blogpost is my last discussion of occlusion alarms. If you’re interested, here are previous posts on the subject:







5 thoughts on “Tandem Occlusion Alarms: The Last Post

  1. I was thinking about you and your X2 occlusion alamrs the other day.

    Might have been related to a firmware update in the pump. Who knows for sure?

    Lilly has a new ‘fast-acting’ insulin now to likely compete with the Fiasp product.

    I’ve read and have seen a ‘possible’ image of a new pump that Tandem has applied for patents, etc. on. Supposedly it is being designed with the more traditional mechanical drive system to push the insulin out of the pump as opposed to the “pressure-type” system in the X2.

    One of the reasons being given by Tandem is that they want their clients/patients to be able to use “all” available insulins on the market as we each have our varying needs.

    So it appears they are well-aware of the x2 reservoir-bladder limitation and its pressure type delivery mechanism. I’m sure they are also well aware of many users using Apidra and Fiasp “off-label” in the X2.

    I thought I had saved a link to the item I found about the Tandem ‘new pump’ under development, but can’t find it in my list of saved URLs (sigh!!). I have no clue as to any type of timeline for such a pump nor if it would have basal-IQ or control-IQ and synch with the G6. I’ll do more detail searching and see if I can find the link.

    My Medicare warranty on my MedT 630G runs out in January-2021 and I’m planning on getting the X2 and starting Control-IQ day one. I’m guessing the timeline will be early couple of months in 2021 for that change.

    FYI … as you recall I had a terrible run of bad G6 sensors earlier this year. Once I crossed that hill all my sensors have worked perfectly and have lasted their full 10-days. That is now a run of 5 sensors without any failures.

    BTW – Did you see that Dexcom Clarity did an APP update and changed the Time In Range values? We can still tweak them to what we prefer. My TIR pretty much stays between 88 and 94 anyway so am pretty pleased with that to begin with.

    Great post as always Laddie.


    Nolan K.

    • Hi Nolan. I always appreciate hearing from you. The new Tandem pump is being called t:sport in development but that doesn’t mean that will be the name once it is released. I frankly don’t know that I will chose it for many reasons but that choice is a long ways off. My current pump goes out of warranty in December and for sure the t:sport won’t be available or approved by Medicare by then. I may continue with an out-of-warranty pump for a while but then if Tandem releases updates to Control IQ, I wouldn’t be eligible. Definitely not today’s problem. Glad Dexcom is going better these days.

  2. I would have gone full on hammer by now. Sheryl tells me that the hammer never solves anything. I say nonsense. I pointed out that a hammer is wonderfully well suited putting a nail in a board. So we know one thing it works well for.

    As for fixing insulin pumps? When a man has a hammer every problem looks like a nail.

    rick 🙂

  3. Thx for the update Laddie.

    There r additional tips I got from Tandem which seem to be a variation of “don’t wear ur pump in ur pocket”. I almost always wear my pump in my pocket.

    For best pairing with G6, recommended to have pump screen facing out of pocket. To minimize occlusions during a bolus (not the primary annoyance you experienced), face the pump toward the body (if in a pocket). The reason for the latter seemed to be related to temperature changes — if we program a bolus in comfy A/C and then let it deliver while in a pocket, apparently the back of the pump will be closer to that AC temp if it’s facing out.

    Most often if I get a bolus occlusion it’s because of that.

    It also seems I’m more likely to get an occlusion closer to the site change “deadline”. I imagine that might be due to a greater accumulation of insulin molecules sticking to the plastics.

    SIDEBAR – Started on Medicare July 1 and have begun to sort out which suppliers I can work with for the Part B/DME & pump Novolog. Grateful for coverage resulting from years of advocacy by so many who came before me.

    Now let’s expand coverage so all who need can have access. Amen

  4. When the tubing coils there is a greater chance of occlusion simply due to change in pressure flow when the coils are smaller and/or tighter.

Comments are closed.