“Insulin Flow Blocked”

I would like to know how many people are getting the “Insulin Flow Blocked” message from their pump, particularly is you have a Medtronic 630G, what you do when it happens, and what you do to prevent it, because it is driving me round the bend!

I was in Boston about 4 weeks ago (I am from Canada) and the first morning after I arrived, I got the dreaded missive from the pump. My usual strategy when this happens is to A) take small manual boluses trying to stay under the “Insulin Flow Blocked” threshold, and sometimes B) go through the infusion set change routine hoping to force whatever is causing the blockage to clear. Sometimes the latter procedure works, but if it doesn’t, and I have a lot of insulin on board, I may change the tubing. If I am at less than 50u on board, I will usually change the reservoir and infusion set and throw away to old set.

I had brought 4 infusion sets with me, for a four day visit, twice as many as I should need, just in case. However, I found another, unrelated problem, in that the clip on the pump was broken, so It fell off my belt and took the infusion set with it. I didn’t realize at first that the clip was broken, and thought I had made a mistake in clipping it to my belt. So I was down to one infusion set by the time I had two days left, so I would be cutting it pretty fine to have insulin for the trip home. Yes, I know I should have had an insulin pen with me, but in the rush of packing, I forgot to put one in my bag. I talked to the international help desk, and they didn’t have any suggestions I could use, but they were kind enough to send me a box of Sure-Ts to replace the ones I had lost.

This brings me to today. I have a method of filling the reservoir that avoids bubbles pretty well, and I am careful to avoid kinking the tube in any way. For most of the next three weeks, I didn’t have any issues with “Insulin Flow Blocked” so I thought I was out of the woods, but this week it happened twice. I sometimes have a bubble of about 0.5mm that I just can’t get rid of, but it usually isn’t a problem. Both times I filled my reservoir this week, I was sure there were no bubbles in the reservoir. I got the first couple of boluses without any problem, but then third time unlucky, I got the message from hell again. I have used the manual bolus strategy to ensure I get the required insulin. (All indications with regard to my BG show that this works.) Also, I am clearly getting the proper basal amounts.

There are a few other quirks of the system that make me want to throw the damn thing out the window, but I have to say that for all its annoyances, the pump has improved my control tremendously. I have had this disease for 52 years, and am getting far better BGs than I had at any time in the past, so I’m going to keep it. If anyone has a positive suggestion to avoid the blockage message, I hope you will share it here. Thanks for reading!

if u are using a cannula set, ditch it and try Sure-T sets which can hardly ever clog. I had countless clogged cannulas and after switching to Sure-T’s that has only happened about once every 2 years. call tech support (NOT sales) and ask for samples. if you like them, have your doc transmit a new Rx for them so that you get Sure-T’s on your subsequent orders.

Looks like Roger is using Sure-Ts.

Note, I don’t have the 630, so my comments may not apply.

@Roger212 - this must be very frustrating! I’m sad you are having to deal with it.

When I get a message like this, the first thing that I do after making sure everything is connected properly is to disconnect the tubing from my infusion set and do a 0.1 manual bolus. If the insulin is flowing, I will reconnect and just continue on. If I then get a further blocked message, then I would change the infusion set, making sure I move to an area that I haven’t used for a while.

For me, the blocked flow message is extremely rare. I’ve now had my current pump for 2 years and I have never gotten that message (JINX!). FWIW, I have always used the Silhouette infusion sets (20 years).

If I find air bubbles in the reservoir after several days and they are near the top of the reservoir, I will reposition the pump so that the bottom of the reservoir is facing up, forcing the air bubbles away from being pushed into the tubing.

i missed that. i tend to skim long posts. mea culpa. (besides which, it’s almost always the case that the issue is caused by the use of cannula sets. :slight_smile: )

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thank you for that, Dave and Yoga. I have limited space to insert the infusion set, as I have been diabetic for 52 years (the date of my diagnosis is about Apr. 19) and used my abdomen for many many years. Also, my arm flexibility is somewhat restriced, so the only thing I can reach is my abdomen.


I use the Medtronic 670G, so I use the same infusion sets (in my case, Quick-Set, which has a cannula). It is rare that I get the Insulin Flow Blocked message, but in a majority of the cases where I do, it is actually a “false alarm”, and it is usually when I am doing a large bolus. Because I have managed to figure out that it is usually a false alarm, what I usually do is wait 1/2 hour or so to see how much it has brought my BG down (or prevented it from rising, since larger boluses are usually for food) and give the infusion set a little time to “unblock” (assuming it was ever blocked at all). Because you can never be sure exactly how much did or didn’t actually go in when this happens, you obviously need to be careful about “redoing” the entire bolus, which is another reason I wait the 1/2 hour. But because it is usually just a “false alarm” like I said, everything is usually fine after that. But if I do continue to receive the message, or it appears to have done nothing (only part of a bolus will obviously make me high, so I need to judge based on how high it is versus what I would expect), then I know that it really was blocked. But it’s a rare scenario that it’s not a false alarm, so it doesn’t bother me that much. But sometimes moving around can help prevent it from getting blocked for real.

This may not be applicable for you. When I’m trying and failing to reach places on my rear love handles or upper buttocks, I find if I turn my body, then turn back and rest for a moment, and repeat the process a few times, I can then reach back there more easily.

I have also used my thighs when I’m in a pinch.

If you have the pump on fast, i suggest changing it to regular speed.

I use the 670G but I think the menus are about the same.

On the main screen press enter.

look for options

look for and select Delivery settings

scroll down until you see bolus speed.

you have two options

Quick and Standard.

Select Standard.

Once people get that set up, it usually will stop 98 - 99%% of the issues.

I was gettign several of these per day and driving me nearly insane. The slower speed will slow down infusion, but it will increase the amount of up time.

If this does not work, or you cannot locate standard speed please call 1-800-646-4633 (option 1). They will ask for your pump serial number. It is on the back of the pump but you can also find it on the status screen under pump.

Good luck!!

Note: I am a Medtronic ambassador. My opinions are my own. They did not pay me to say nice things about Medtronic devices or the company. OK, they sent me a shirt and a cup but even I am more expensive than that**.

Really its true, I do not work for Medtornic in any way. I do not even have stock in the company. I double promise***


@Roger212 have you been able to get to the bottom of this? I’m having the same issue and it’s progressively getting worst. Can I ask what brand of insulin you are using?

I’ve had my pump replaced, infusion sets replaced and continue to get this problem. I’m using the medtronic mio and apidra (insulin). When I first started pumping, I didn’t get this issue at all for at least years, and since getting the error, the issue wouldn’t go away. So frustrating.

You are using a set that can kink! I had as many as two kinked cannulas per week, when I used similar sets and had to change to a steel set or stop pumping altogether because of all the missed insulin, especially at night with only basal. Do what I mentioned on your thread and change to steel sets!! Keep in mind that if you have major scarring at your sites, even with a steel set you might sometimes get very poor absorption and/or blockage but at least it won’t be from the far more typical cause of a kinked cannula. The tougher the tissue, the more likely the kinking will occur.

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I haven’t had issues with kinking on the Mio. When I inspect it visibly after a blockage and removing from the site, it looks fine and when I prime manually using a plunger insulin flows through as well. I don’t think my blockages are to do with kinking however I will try a steel set just to rule everything out. Thanks


It never hurts to try (and literally, I find Sure-T’s far more comfortable than cannula sets which leave me with marks, bumps, more trauma, soreness, and redness–all things that don’t occur when I use Sure-T’s). You would find it difficult to spot where my last Sure-T was installed.

I frequently got blocked insulin when using 9mm cannulas but switched to 6mm and all that went away. The longer ones kinked often!. Cheers