Question regarding G4 and Hourglass symbol and?

I just got my Dexcom G4 this week. I had the Seven and I am delighted that this CGM is more accurate.

The question I have is that every time after taking a shower, my receiver has the hour glass and then is followed by question marks.

Do any of you cover the transmitter when taking a shower? My receiver is on the bathroom counter - not even 10 feet away from the shower.

Any insights would be appreciated!


I had the same thing when I first started and realized that it was connected properly. make sure that both side clips on the device are connected to the transmitter.

I haven’t had that problem. Have you called tech support? They are very friendly and helpful.

If the sensor's contacts gets wet, it will only spit out "???" for a while. I've unclipped it, wiped it off, and it works again quickly.

I have gotten similar experience I think that it may be a case of water getting in between the sensor and sensor case In these cases I toweled around the area and waited after a while it seemed to come back. Several times I also noticed that the sensor wasn't seated properly into it's case. I pushed down on it and it snapped back in place soon after the sensor was sending normal data. I might also add that sometimes it never comes back until I change the sensor. I normally monitor it for about an hour before changing it. Hope this helps.

I too have had that happen and for the longest time (over a year) covered it with Tegaderm. I don't do that any longer. Another poster suggested I place the Tegaderm first and the position the sensor vertically (I use my belly) rather than horizontally. It is suppose to help with drainage. It does; I haven't had the dreaded ??? (without placing the Tegaderm over the transmitter) since I changed placement position and I do put the sensor on top of the Tegaderm now, rather than under it. Best of luck to you!

Thank you to the other posters for your suggestions of taking the transmitter off, drying it, and putting it back ... should I happen to get the ??? ever again, I'll give that a try!

I think it is water getting in. So I will try this.

The Seven had to be covered in a shower - so I am taking their "waterproof" very lightly....

I am also noticing this happens with exercise... the sensor seems to get confused sometimes... it comes back - but it almost defeats the purpose of having a unit since I am most interested in what is happening with exercise. Like - am I dropping too fast????

I do think it is water. When I had a Seven unit, we had to cover the transmitter and sensor when taking a shower.

It's waterproof in the sense that it isn't damaged by water. If you unclip and see the contacts are wet, then they simply need to be dried off. I never had any waterproof issues with 7 or G4. Sometimes I've layered tape over the top side of sensor while showering, but this is mostly to prevent water from getting near the adhesive, so it could stay stuck a little longer. I use my Dexcom while exercising all the time, and while the "???" does happen occasionally, it hasn't been a major issue for me.

Hi, Susan -
The obvious solution is to not take any more showers. If you have some reason for not wanting do that, then we can probably say that there are at least a couple of things that can cause Dex's "confusion" after a shower. Water impacting the signal, as has been suggested, is one. Another is that warm water beating on the sensor can loosen its positioning and destabilize where the sensor senses. I don't pretend to know what the cause is, but I can say this: I don't have this problem.
You commented on another post of mine implying that you liked the idea of taping down the sensors as I had described. I get 3-4 weeks out of each one by keeping them taped down. The taping also serves the purpose of either a) keeping the water out sufficiently enough so that the water doesn't cause a problem or b) keeping the sensor stabilized enough so showers don't cause a stability problem. Either way, it works for me. I use hypafix and skin-tac. Other people use other methods. Try it. You may see an improvement. Good luck.

Is there a lot of metal in your shower wall/door? I never have a problem with reception while in the shower. But my shower doors are rather cheap. I doubt it's water causing the problem. More likely it's interference on the radio from a lot of other possibilities in your bathroom.

Nope. Shower curtain...That is why I find it strange. LOL

:) I think it has to be the water - it does come back. I will be experimenting with tapes and the various suggestions made in the other post.

Fun device so far though and much improved over the 7!