Restarting G6 sensor failed? Help!

Restarted a G6 sensor on day 10 and it told me “single start sensor”. It got as far as starting the 2 hour warm up. The transmitter is 8H and was activated on 12-9-19. Any options? I used the no code 15 min warm up followed by the real code and it started the 2 hour warm up.
I’m using the Dexcom receiver.

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Well this is weird, I was looking for the transmitter number and I noticed I had the option of “pairing” the transmitter and sensor like you do with a brand new one. So I tried that and they paired, so now it’s going through the sensor warm up. We’ll see if it works.

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Nope, failed again. I’m starting a new sensor.

Some have reported it requires 30 min wait, or physically removing transmitter and wait.


Did you physically take the transmitter out of the sensor?
That is all that seems to be needed.
I let xdrip do the work of restarting it, but I have to remove the transmitter from the sensor for it to start over.


Hey @Jan! Sorry so slow to respond. I have also heard some people say they need to remove the transmitter and wait 30 minutes. If I’m not mistaken, it’s the same process as it is hot the 8G transmitters, but did your message actually use the words “single start”?? I’ve yet to see anything like that.

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Yes, I should have taken a picture of it, but I didn’t think of it. It said “single start sensor” and something about a new sensor must be installed.
So, I went ahead and started a new sensor, and I’m waiting through the 69 with straight down arrow to 122 with no arrow at all, and back and forth, which I hate so much. Why doesn’t Dexcom just get it approved for 30 days.
I get anxiety every time I have to start a new sensor. Worrying about a bleeder, whether or not it will fail, and the shenanigans it always shows at the start.


When you get those shenanigans at a new start, do you do any calibrating? Or do you just wait it out?

That sounds downright miserable, @Jan. I’m sorry this is your experience. In all honesty, I do have some duds, but the majority of my sensors are solid. I will even say (then knock on wood) that my first 24 hours is usually pretty accurate—accurate enough to be able to leave my meter in my bag at least. I also get good distance with mine (though do take a hit in signal as the days pass by).

First day sensor… In general, I wouldn’t really bother calibrating. The sensor needs probably 12-24 hours to settle down. In the beginning, I was calibrating once I was in for at least 12 hours when I just wasn’t comfortable with the discrepancy. I wouldn’t have touched it before then. Over time, I’ve settled into not calibrating at all. My only explanation is that whatever little bumpiness I was experiencing in the first 12 hours was probably settling by the time I got to 24 hours. That makes me think that I can choose to calibrate early or just ride it out—and both roads seem to dump into the same performance. Generally speaking.

I started this comment like an hour ago and bored myself into a lull, and now I can’t remember the point. I think you mentioned first day calibrations as well as sensor errors upon restart attempts. The only thing I can say about those (having not worn either the 8G OR 8H transmitters yet) is that just getting a message saying you can’t restart doesn’t mean you can’t restart. I have attempted it as many as 3 times before getting it to work—and I still don’t know what I was doing wrong or right. Again, I’m not sure if the same is true for these transmitters.

I hope this message isn’t as unclear as I think it is. I would try to look it over… but just can’t bring myself to do it. :grin:


Completely Agree.

Ha ha ha
Yeah. I do that also.


Hi Everyone,

I have a 8H transmitter and it took me quite a while to find a reliable way to restart my sensors.

The way to restart a sensor with an 8G/8H transmitter is this:

  1. STOP the sensor. (Note 1)
  2. Remove the transmitter from the sensor using blood testing STRIPS. (Note 2)
  3. Keep the transmitter out for 20 minutes (Note 3)
  4. Put the transmitter back into the sensor
  5. Start the sensor on the app using “Start New Sensor”. Enter its correct serial number. (do NOT use 0000)
  6. Wait 2 hours
    BINGO it works again.

Note 1: I did this using the G6 app, but you can use xDrip+ or the Dexcom Receiver.
Some people bought the receiver JUST to do this part, but that seemed like a lot of money to me

Note 2: There are a number of good videos on YouTube showing how to do this. Just search for “Removing G6 transmitters” and you will find them.

Note 3: You DONT have to put the transmitter in the microwave or a special Faraday bag. Just keep it out of the sensor during this time. Some people say 15 minutes, some 20 minutes and some 39 minutes. I did 20 minutes, but if you want to wait longer, it is fine too. Just remember that you will have a 2 hour warmup time as well.

Best wishes and Merry Christmas


Excellent and concise set of steps.

We are still on the 81xxxx with an 8Gxxxx on the shelf.

When we do get to the 8Hxxxx these will be very helpful.

(Edit: I just realized you said this was for both the 8Gxxxx. AND the 8Hxxxx.)

We have practiced popping the G6 transmitter out from the sensor housing without breaking the housing using a pair of strips. Like picking a lock. Takes a little feeling around but then it pops.

I was surprised this was not required from the initial launch of the G6 with the 80xxxx. Otherwise what was the point of typically having to physically break the sensor housing while separating the transmitter.

In any event thanks for the clearly written set of steps to restart the 8Hxxxx transmitter.


Thanks so much for the great set of instructions! Will use these when my current sensor expires.
Can you let the sensor just end, or do you have to manually stop it?
I usually like to stop it a little early so I have some time for it to settle down before bedtime.


Thanks for this, @Tigs1962! It’s very clearly written and easy to understand. You don’t have any idea how to restart the transmitters, do you?

Happy Holidays to you, too!


Hi Jan,

Sorry, i missed that bit.
This is the one thing that I am not absolutely certain of, because I haven’t tried myself to let a sensor end THEN do this.

Every time I have restarted my sensor, I have done so about 4 hours beforehand. However, some people actually do it on day 9. I can see the advantage of this, just in case you do something wrong and need a second try.

As this method allows you to restart the sensor as many times as the sensor can continue to provide good readings, it doesn’t matter if you restart it day 10, day 9 or day 5 really.

Good luck


Hi Nick,

The transmitter batteries last about 3 months. However there is a guy called Craig Billy Waugh on Facebook who runs a service where he replaces the batteries.
You send him your transmitter and pay him £50 and he sends you a replacement transmitter.
His Facebook group is called:
CGM transmitter battery replacement UK


The transmitter usually runs up to 112 days, then dexcom app or receiver will consider it done. (But xDrip keeps reading).

To RESET the transmitter internal transmitter days counter, you can use xDrip reset command (engineering mode) on android phone. (Using RESET instead of restart helps to not confuse with sensor restart.) XDrip reset updates the transmitter day count on the transmitter, so once complete, standard dexcom receiver/app thinks it is new.
Can also be done from Spike app on iPhone. But still unconfirmed if newer transmitters allow this.
I was successful on reset transmitter starting with 80xx, using xDrip. Soon will try with newer xDrip version and 81xx trans.

Here is another discussion.


Thank you, @MM2. I was asking it the wrong way. I was actually looking for the answer for @LarissaW. I’ll go hand deliver it now. :slightly_smiling_face:

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@Jan - I use the same method @Tigs1962 shared and can confirm it restarts sensors once the session has ended, not stopped manually (I’m currently using an 81x transmitter).


So does that mean that I have to let the sensor expire completely before I can restart it?

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