I think the watch detects stair climbing by simultaneous detection of walking an altitude change. If you climb stairs holding the rail or doing something else with your arms that could fool the step detection mechanism, then stair climbing detection would also fail.
I thought this myself so after checking the manual I have made a point of not holding the stair rail, using my arms as normal and taking my time going up the stairs, I have also tried running up the stairs and making sure I extend the length I walk away from the stairs at the top so the Garmin knows I have stopped ascending, they all make no difference. Last Thursday at the gym which has a fight of stairs which is double the size (steps) in my house, I tried various modes of walking and running up the stairs, not holding the bannister, the stairs climbed which were recorded was intermittent, some it would record and some it wouldn't, I ran up and down the stairs 50 times but it only recorded 28 and it froze at that. There is a problem here, I previously had 2 different Fitbit's which I got rid of because of all sorts of problems but the one thing they both did with extreme accuracy was recording stairs climbed. I had thought that changes in barometric conditions might effect the Garmin but then you would have expected the Fitbits to have the same problem. I was wondering if there is a way of calibrating the Garmin for stairs as you do for treadmill runs but I can't see how this would work if the stairs climbed is based on barometric readings.
Just spoke to Garmin and the very helpful person I spoke to wasn't aware of the problem but he checked with the technical department and then read out a statement to me. Basically what I believe he said to me was Facebook Live track had been removed at the moment due to changes because of the recent privacy changes face book have made and are making. There was no indication when this might be available again by the same rule there was no indication that it wouldn't be. I did ask if this could be made known to all Garmin users and the gent did say he would see what could be done. I have tried the Twitter facility but it doesn't seem to be as good as the face book one, not tried the email tracker yet as I cant get my head round how much data this may use.
Sorry I have posted my last message to the wrong page. This issue was regard to the fact that Face book doesn't track my walks and runs anymore, nothing to do with climbing stairs.
I seem to climb a lot of stairs and I live in a one story house and my fitness center is also one story and nope, no stairs in the neighborhood. However, my watch shows anywhere from 4-10 flights of stairs climbed most days.
I have tried everything to see which way of walking up stairs works best for recording them, I have climbed them fast, slow, swinging my arms, two steps at a time, one step a time, exaggerated walk and arm movement, but there appears to be no set way of walking, I think I will report this to Garmin to see if there is a fix to it.
I reported this a in September and I was asked to reboot the watch, made no diffrence and now it is getting worse. this coupled with the fact I cant be tracked when out exercising via Facebook anymore (which worked perfectly) makes me want to return the watch. I will try and ring then again but while they always seem very interested at Garmin they seem to be problem takers and not able to resolve anything. I have tried being tracked using the Twitter and email feeds but they are very unrelaible. I have gone from thinking the Gramin was the right choice to thinking I made a massive mistake.
The problems seem to be getting worse, today while out walking I walked up and down a hill (with stairs) which normally records as 10 flights of stairs, so today I thought I would go up and down this 5 times in the hope it would record 50 flight of stairs it did around 25 and then froze out. I am convinced there is a bug in the system with regard to the altimeter or barometer, next time I will try this by walking down the hill in a different area to see if the watch needs a few minutes in between climbs and therefore if it records them any better. I now have problems sharing my walks on face book, after the fact, which until last week I could do with ease, when I try to share via the weblink it stares error has occurred. Also on top of that I haven't received for the past two weeks a notification on the Monday of each week that my stats are ready to be viewed in relation to a group that I am in where we have a table of who has walked the most steps.