Repeated Dexcom G6 failures


AND I am now on sensor 7? or maybe 8? and we’re not even 2 months into our G6 usage – more like a month and five days.

Tonight his sensor (Which was about 5 days old) failed and the new one immediately said “replace sensor” after just 20 minutes in the warmup period. We’ve tried different places on the body, no IV prep, yes IV prep, etc. etc. It just doesn’t seem to work as well for us as the G5. When I went to my endocrinologist, she said only one other patient is having problems with the G6. She said it was a person in “very tight” control although I don’t really think Samson is in tight control. And in any case he is often getting the data dropouts when his BG is high.

Talking to the Dexcom people on the phone, they seem to say there’s definitely no problem with the transmitter because they can actually read something from the data they get on their end – but that makes me feel MORE discouraged. If it was a bum transmitter they could just replace it. If something about the insertion process is just not workable with the G6, I don’t know what we’re going to do. We can go back to G5 but in the end we need to know we’ are not operating on borrowed time.

We got 3 extra sensors from a very kind person on our list-serve. Dexcom also sent us an additional 3 sensors for those failures. We now have 2 left and we’ve got 2 months left on these transmitters.


I’ve just noticed this thread, sorry to hear you are having issues with G6 sensors failing repeatedly, that’s really frustrating. Based on what you’ve described, I think there must be something wrong with the transmitter. It is not impossible to have some issues in the transmitter that would be undetectable in whatever data Dexcom is receiving. I’d just request a new transmitter from Dexcom. If they continue to insist that there is “definitely no problem with the transmitter”, I’d try to raise this the request up their support chain. You may offer to send the transmitter back to them so they can run more detailed diagnostics on it.


Yeah I think we will do this if we keep having problems. The other thing I’m trying is basically to just not bathe Samson’s arm so he isn’t getting the transmitter wet at all (not a long-term solution obviously, LOL). We’ve switched him to showers from baths and it’s occurred to me that maybe the water is being pushed with more force into the little gaps where the sensor is attached. So far we haven’t had any data drop-outs with this sensor and it’s now going on 2 days, so here’s hoping!


my goodness. reading all of this makes me feel grateful to Medicare for not approving the G6 till next year.

i just started on the new G5, and it is up and working well, found an accurate sensor site (upper left thigh), and despite all my days swimming in the pool, have had no problems with it pealing off (am using, though, a little skin tac)

i was on the G4 and the G5 a number of years back, and i had nothing but problems with both of them. i spent more time on the phone with dex tech support regarding replacement sensors than i got days out of working sensors. yup, it was actually that bad.

will say some prayers for all of you and hope that the glitches work themselves out.
PS: have had several questions for tech support and was on hold each time for over 2 hours. thank god for speaker phones and my undying patience. :sweat:


How do you restart the transmitter after 90 days? I have wasted a sensor or 2 when it died on me 2 days into a session.


That’s not supposed to happen. In theory, they won’t start a new session unless there’s at least 7 days left before the sensor deadline. If it was an old transmitter (i.e. not fresh when started) I suppose the battery could fail unexpectedly. In any case it shouldn’t waste a sensor, just carefully spread the two clips on the sensor that hold the transmitter in and the old transmitter will pop out. Then insert a new transmitter. Press the new transmitter in really hard until you hear the two clicks.

I restarted the G5 transmitter following directions at http://seemycgm.com/2018/06/11/restarting-g6-sensors-and-transmitter/


Thank you. I will try that if it happens again.
I was afraid to remove the transmitter from an inserted sensor. And I was not told by Dexcom about a session not being able to be started within 7 days of a transmitter’s end of battery life, so that’s very interesting.
I’ve learned a lot about the actual longevity of the sensors from this blog, too!
Thanks again!


its not a waste if you just call dex tech support and report it. they replace it for free; no questions asked.


UPDATE: So, after digging around I found an offhand comment somewhere in the Dexcom documentation about moisture affecting sensor readings, which could lead to blackouts until the moisture inside the housing dried out. Anyways, I remembered that a week or two before Samson started using the G6, we had switched him from taking baths to giving him a shower, and his arm usually got a lot more spray on it as a result. Also, he didn’t shower every day, but typically every other day – and we often started getting errors on day two, although sometimes on day one. And then I remembered that in the past with his G5, his sensor would often fail on the day that he would go swimming, or very shortly after.

I had tried everything else I could think of; switching to the stomach, following their rules exactly, using Skintac, not using Skintac, using IV prep, not using IV prep, holding the applicator flush, pinching up, etc. etc. etc…

So while I wasn’t convinced that the showering had anything to do with the issue, I was desperate and willing to try anything. It had to be better than just calling Dexcom every three to five days and having them say “oh it’s just a sensor issue and did you put it on the abdomen and wipe the transmitter with rubbing alcohol?” then hoping the new replacement sensor came before I totally ran out of supplies.

Anyways, about five days ago we finally put a new sensor in that worked initially, and instead of having him shower, we’re having him bathe and making sure he keeps the arm with the sensor totally dry. So far, we haven’t had a single dropped reading. No data blackouts whatsoever, and those typically started by day one or two with all the past readings.

Coincidence? Very possibly so… But on the off chance it’s not, we’re going to ride this sensor as long as possible and make him take baths instead of showers for this sensor and the next one. That one arm may possibly be pretty dirty at the end of this whole experiment though. :rofl:

Of course, we’re only on day five, and though the sensor is going strong so far, it still hasn’t made it the requisite 10 days yet. So the jury is still out for sure. But if it turns out that moisture is the problem, then what the heck do we do? Swearing off showers for the rest of Samson’s life is not really an option (though he would probably not mind.)

Are there any tips to make the sensors EXTRA waterproof or moisture proof?


This sounds awful. as you know, i am a swimmer. i am in the pool for almost 2 hours a day, 5 days a week, followed by a nice hot shower in the locker room.

i used the dexcom about 3 or 4 years ago and had similar problems as you are describing. i was on the phone with tech support every other day. the belly didnt work for me (i am too thin). i tried my hip, my tushy, etc. nothing worked. i went “out of range” at times where i was carrying the receiver in my back pocket; and, it either wouldnt come back on for hours, or it wouldnt come on again at all. so i gave it my best and decided to just return to (many) finger sticks.

but, then Medicare approved the dexcom 100%, and i decided i had nothing to lose by trying it again. i am on the G5 currently. i havent had many problems at all. i do use the skin tac to keep it on for my swimming, but other than a few “lost signals” i have had few problems. i am currently wearing it on my upper left thigh, which has been a good site for me. ( i tried the back of my left arm as well as my upper back, but didnt get the accuracy i wanted).

all this to say, that maybe you have had terrible luck with the sensors themselves. are you on the G6 now?

(and believe me when i say i have endless compassion for you, b/c although i dont have “water” issues, i have others that carry their own frustrations.)


Try wrapping his arm in Press-n-Seal?


Maybe try a waterproof overtape like Opsite Flexifix and tape over the entire sensor instead of cutting out a hole for the transmitter. I think Dexcom also sells or can give you overtape that covers the sensor but its only sticky around the edges (so it forms a kind of “bubble” over the transmitter).

I think when I first tried out Dexcom like 14 years ago we were actually instructed to put their overtape over every sensor because of the moisture. Seems like they should have improved the design by now but maybe not! (though I never taped over my G5 transmitters and didn’t have problems)


2 posts were split to a new topic: Multiple calibrations needed by G6 sensor on startup


@TiaG, has Dexcom refused to send you replacements for every failure?

We have occasionally had some problems in series with G5 sensors and have sometimes asked for 3 sensors in the same week. They have never given us trouble. I ask every single time, unless it fails the 7th day.


We have gotten replacements every time. They’re great about it and never argue, if if it fails at day 9 and 22 hours. But if the sensor is only lasting 3 or 4 days, it’s still incredibly problematic for us. Samson hates sensor changes and he needs numbing cream so it’s a 3-hour process for us, and having them fail unpredictably while he’s at daycare means I need to take off every time.
The other problem is that this rash of early failures coincided with my husband losing two-months worth of sensors. So we were already running low, we managed to get about a month supply from someone else, but with all the frequent failures we were just always on the brink of running out.


You are using numbing cream still for the G6?

We just put our first G6 on (3 days ago?). My daughter was quite apprehensive as she REALLY does not like the G4/G5 sensor insertions.

I hit the button (on the G6 inserter) and she asked, “Did it go”? She thought maybe it was a “misfire” as she did not feel anything. She was pretty surprised to see that it actually went in.


My son’s experience with the G6 sensor in the first few weeks is very similar to what you have been experiencing. The first sensor lasted eight days (not bad), the second sensor went for four days, the third sensor lasted for less than a day, sensor four ended without a single bg reading and sensor five ended within twelve hours of insertion. Dexcom has been very good about replacing the failed sensors but didn’t have an answer about what may be causing our failures and just recommended careful transmitter cleaning and moving to more fatty sites on his abdomen. We experimented with the replacement sensors Dexcom mailed to test if we had a bad production batch, but had similar issues with both replacement sensors.

We’re baffled and frustrated as well about our high failure rate, as the G6 insertion is a breeze and so much less stressful for my son when compared to the G5. The first sensor, with eight working days matched with the updated Tandem software, resulted in a significantly tighter bg range, so we’re really hoping that it’s just a bad set of sensors, but I plan to contact Tandem to see if there could be a software issue or perhaps as issue with the iphone app. Wondering if anyone is having similar issues with other pumps, including the Omnipod?


Have you tried switching to only using the Dexcom G6 receiver as a way to eliminate variables and reduce the possibilities?


That could be a nice way to start debugging.



Thanks for your suggestion. I plan to test that option this evening when my son comes home from school. Everything so far has been through the app and the Tandem pump’s CGM reporting.