G6 'restarts not allowed' error message on new sensor

I’m a relatively new G6 user, started four months ago, and ran into a “restarts not allowed” error message on a fresh first-session sensor. I’ve followed many of the prior threads about restarting G6 sensors and am aware of the various reasons people give about why the G6 algorithm throws this message.

I called the Dexcom global support phone center and learned something that I hadn’t known before. I apologize if this has been covered and I overlooked it.

What I did was to insert the sensor last evening as I wanted the sensor element to settle in and report stable numbers sooner in the active session. This pre-soaking tactic has worked well on a few prior sessions.

This morning, I stopped the current sensor and then quickly moved the transmitter over to the new sensor after cleaning the transmitter contacts. After 30 minutes of the two-hour warm-up period, the “restarts not allowed” error appeared and sounded.

I didn’t want to mislead the tech support person and told her that I inserted the new sensor last evening but did not start the sensor until mid-morning. She told me that if a transmitter is stopped and then started within five minutes then the algorithm concludes that the user has restarted a sensor.

Since my new sensor was already in place, I was easily able to move the transmitter from the old to the new site quickly. That five-minute rule is news to me.

She happily offered to replace my sensor. Diabetes management is a continuous learning process! I don’t mind the challenge but I fear that these kind of incidents will be tougher to manage as I age.

Has anyone else run into this five-minute rule violation?


When I do restarts, I wait at least 20 minutes, since less than that I would get that message.

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That shouldn’t really happen if you aren’t attempting to restart the same session, so I’m trying to figure out what might have occurred. The presoak shouldn’t make any difference—it’s really the same process, whether you inserted the sensor the day before or just before switching the transmitter over in the usual way. The only tricky thing I’ve ever had with a presoak is remembering to hold onto the bit of peel-off paper with the code, which I did once, so I always take a photo of it. With a restart, you’re re-entering the SAME code, which is the gotcha, hence the whole rigmarole about removing the transmitter without pulling the sensor off and waiting 15 minutes before clicking it back in and doing the rest of the “new” sensor procedure. This apparently clears the memory bit that holds the code, so the system thinks it’s a new sensor. But with a genuinely new sensor I’ve never run into any time limit whether I’ve presoaked or not. Only thing I can think is if the new sensor had the same code as the old one, which could happen. A lot of us have noticed that the same few numbers turn up repeatedly—I have concrete proof because I always take a picture, and I have several repeats in that photo gallery. Other than that I can’t see how the presoak thing makes any difference. I don’t even think Dexcom has a policy about that practice.

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But he wasn’t doing a restart; he was starting a new sensor after a pre-soak.

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As a footnote, the whole “code” business makes it seem like the sensor is locked to that number, but given that they do recycle them I have wondered whether I could do a restart using one of the others I’ve saved and not have to go through that whole elaborate restart procedure. As in, maybe it just checks to make sure it’s not the SAME number, but other than that it just has to be any valid number from the list. Because they definitely do recycle them.

I always take a picture of the peel-off paper with the code printed on it with the peel-off paper of the applicator that includes the lot number. My phone handily stamps photos with a date and a time.

Lo and behold, the last sensor that I started with a code was the same number. But I did do a no code restart session in between that lasted four days. I think there may be something to your thinking. The five-minute separation between the sensor sessions might be true but I’m not fully sold on that idea.

I read somewhere or may have been told to allow at least 20 to 30 minutes between turning off an old sensor and starting a new one. Have always done it since I started g6. Never had that message.


Thanks for your comment. I don’t remember seeing that but your experience supports the idea that some minimum time between non-restart sensor sessions is required. That would back up the statement made to me by the Dexcom rep that at least five minutes between consecutive sensor sessions is needed.

I know, however, that I’ve initiated a new sensor with much less than a 20-minute interval and have not received the restarts not allowed error.

By the time we get this all figured out with our collective experience, Dexcom will have rolled out the G7!

I was told by Dexcom support to wait 15 minutes, it is a nuisance as I can change much faster than that. Seems like everyone is getting different lengths of time to wait.

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Plus we have to wait for the two-hour warmup before getting any numbers.

If you read the instructions that come with a new transmitter, it actually says to wait 15 minutes.


I spend more than 10 minutes slowly peeling the old sensor off my belly before moving the transmitter to the new site.

If anyone can remove the old sensor in faster than 5 minutes they are experts compared to me!!

I’ve gone from one to the other in less than a min with no issues. I’ve even used the same code becasue often in a box then are all the same code.


Curious. I’ve never bumped into this problem.

But the transmitter was moved from old sensor, then put onto the pre-soaked sensor within less than 20 minutes. So from transmitter point of view that is similar to restart.

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I see other people saying they wait 15 min. for a regular (not restart) sensor change, so I guess I have to accept it’s a thing, but I’ve never done it and never had any problems. Usually less than a minute for a pre-soak, since the sensor is already in place and all I have to do is yank the old one out, remove the transmitter, and click it in place on the new one. Maybe two-three minutes, tops, including the bit of entering the sensor code. But twenty??? Never.


Lots of comments, but not a single one on the fact that this expensive piece of equipment can serve accurately for a lot longer than the artificial time limit given it for corporate profit reasons(?).

The coming g7 will last for 14 days and include the transmitter. Then both will be discarded into the waste in our countryside with absolutely no forethought of coordinated recycling for reusable materials. All of this rankles me while I merrily go on using and discarding… :partying_face:


Yes! And just to point out this applies to both transmitters and the sensors. The fact that there are people out there that are able to replace the transmitter battery if they have the tools suggests that a better design for the transmitter would have been to use a rechargeable battery. In this day and age with technology, this is not a far fetched idea, and I would have thought would be quite easy to achieve.

At a very minimum, they should have given access to battery compartment so that you can slide it open and change the battery yourself. But instead they have chosen to make it difficult so you need to discard the part creating unnecessary land waste and make you buy a new one for a few hundred bucks when a new battery is just a few dollars. Seems a bit wasteful to be honest. It’s very obvious that the bottom line influences a lot of these decisions.

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I’ve often wondered about this and have come to believe it has to do with keeping it water tight.

If it were a regular batter compartment, with open areas anywhere, I/you wouldn’t be able to shower or swim with it on.

I don’t like the waste or the expense, but I am coming to understand the reasons why.


Yeah, I share your discomfort. These devices that are so useful for helping us stay alive aren’t designed with a conservationist philosophy baked in. Somehow it seems like those things should go together.