16.17 - Inaccurate calculation for total ascent and descent

The watch arrived yesterday after being replaced by the service center. And you can immediately see the differences in the height readings. In watch mode, it is stable, there are no strange drops or rises. During training it was also very good, in the old one I had over 120 m on a known route, on the new watch it was 16 m (correct). To sum up... these are the values I had a year ago after buying the watch. So the one I sent for service must have broken down.

To the service from Poland. At the beginning they also said to clean the altimeter holes, calibrate, etc. Of course, nothing worked.
Then I presented the correct training that I had a year ago and those that I had with bad values. And they told me to send a watch.

thanky you, im from Slovakia, I will try to write too...but I think that each service will approach it differently...

I think so too, it depends on who you get. Good luck.

I wrote last week to global Garmin support.

And I received email from Czech garmin support yesterday. They asked for more information.

I will see what will be the result.

I'm from Estonia and i had a same case with my watch altimeter. I wrote to garmin product support in the mid october but got no answer. I wrote again on friday and on monday local support sent me e-mail and agreed to change the watch. I havent got the new one yet, it should arrive in the end of this week or in the beginning of the next week. I hope my altimeter problems will end then. I think its maybe something to do with the early version of the 955 watches. I bought mine on 02.06.2022, just after release.

Hmm. I bought it in April 2023.

I tried to run the same route with my Fenix 6 yesterday and there is the same altitude issue. So, now I don't understand at all.

I have a Forerunnner 955 Solar and also have noticed that total ascent and total descent are almost never the same when I start and stop my runs in the same location. The ending elevation is almost always higher than the starting elevation (usually 20 - 50 ft higher). I always calibrate the altimeter to a known start elevation or to the DEM before I start each activity. I understand there is some level of inaccuracy from the altimeter, but it seems like it consistently drifts upward, even on shorter runs. I usually run on trails, but I noticed that the elevation also drifts higher when running on roads. The elevation usually stays the same when I am at my desk during the day.

Infrequently, the starting/ending elevation and total ascent/descent are sometimes very close. On a trail run last week, I ran up and down a small mountain 8 times and the elevation and total ascent seemed correct. The starting and ending elevations were also really close, even though it was raining/snowing the whole time. I expected bad weather and lots of elevation changes to only make the drifting worse, so I am kind of confused by this.