3 Week Old Fenix 5 - Wacky Altimeter

A lot of F5 owners have had this problem. Apparently, the ambient pressure sensor is sensitive to static electricity from your clothes.

Recalibration will not help in this case. The word "recalibration" implies that you are doing something to make the hardware more accurate, but that is not really what happens. The recalibration simply sets a reference pressure which the current ambient pressure can be compared to when the watch calculates altitude. But if your ambient pressure sensor is acting up, this reference pressure will also be wrong.

Some owners have had luck submerging their watch in mild soap water. This treatment will only last a couple of days.

Edit:
You can see the measurement of ambient pressure if you make a custom data screen in an activity and add the Ambient Pressure data field to this screen. Do not use the Barometric Pressure data field, since this will show a calculated value, based on ambient pressure and assumed altitude.

If you are at sea level, your ambient pressure should be around 1013 millibar +/- 30-40 millibar. If you are at higher altitudes, the ambient pressure will be 1 millibar lower for each 8-10 meters of altitude. When the problem occurs, your ambient pressure will probably be several 100 millibars off from these values.

This is a design flaw and the watch will be going back for a replacement until I get one that does not have this problem. Unacceptable.

Yes, it is probably a design flaw. But in that case, what do you think you will achieve by sending it back and getting another one?

If it is a design flaw, all watches of this model are affected.

If you can't accept it, get rid of the watch. Find another model which doesn't have this behavior. The Fenix 3 (non-HR model) didn't. So far it also looks like the Fenix 5 Plus doesn't.

Yes, it is probably a design flaw. But in that case, what do you think you will achieve by sending it back and getting another one?

If it is a design flaw, all watches of this model are affected.

I will expect that Garmin recall defective watches and solve this issue. It's unacceptable to spend about 600 euro to buy a top watch and have this kind of problem.

Given the enormous and rapid variance you are seeing in elevation, and that you’ve tried a factory reset, the only conclusion is you got unlucky and the watch hardware is faulty. Given you are well within any initial return period, take it back to the shop and get a replacement.

These forums are filled with stories from users who have repeatedly returned their watches and received new watches, all with the same altimeter behaviour.

I am convinced that all Fenix 5 watches have this behaviour when it is triggered. But not all users will be able to trigger it, because they have different daily routines, different clothing, different air humidity or whatever.

So if you are one of those users who are able to trigger the problem, you have these choices:

• Get a watch of another model. Not just another watch of the same model.
  
• Change something in your routine so you don't trigger the problem.
  
• Accept the problem.
  
• Wait for Garmin to fix the problem in hardware (which is really just a variation of choice #3, since I doubt this will ever happen.)
  

Those that have repeatedly seen Altimeter issues on the Fenix 5, are not typically reporting these wild rapid swings in elevation, but rather their issues are more subtle (unexpected or not matching elevation gain/loss, overly smoothed elevation plots and others). The Fenix 3HR did have a long standing hardware issue that caused these big swings in elevation, experienced by many (even after multiple replacement units), but that issue seemed to be sorted once revised hardware versions made their way through the manufacturing/supply system. There have been nothing like the swarm of reports seen on the Fenix 3HR forum a while back, to suggest the same problem is endemic on the Fenix 5. So I still maintain, take the watch back and get a replacement unit; only if that second unit has the same issue should you concede that your usage disagrees with the Fenix 5 and look elsewhere (perhaps 935, not seen any wild rapid elevation swings reported on that forum, that weren’t fixed with a replacement unit).

Well, I swapped my first copy of the 5 with another and have re-set it up just like the first. So far for the first hour after setting the elevation it's been rock steady as I type this at 10 ft above sea level here in Seattle. Even if it is a design/reliability issue there must be some watches that don't fail like this, so swapping it out for a new one is a valid thing to so. Unacceptable to live with a faulty component such as an altimeter on an expensive watch such as this. The replacement was a display model and came with 2.4 software, so clearly it had been sitting in the case since they first day this model came out. My first copy had a much higher software version than the second indicating it was a much more recent version off the production line. If this 2nd copy suffers the same problem there will be a call to Garmin directly as I have personal connections through one of their largest retailers. I'll let you all know how it goes in the next weeks.

EDIT: I did go ahead and update this second watch to 12.0 from 2.4 before calibrating the altimeter.

Those that have repeatedly seen Altimeter issues on the Fenix 5, are not typically reporting these wild rapid swings in elevation,

These wild rapid swings were exactly what they were reporting when they had the static electricity problem.

I'm late to the discussion of past problems, but how exactly did they definitively determine it was static electricity that was causing a problem?

24hrs and so far so good. Though I have yet to go running, running in the rain, take a shower, etc. If we make it through a week of "normal" use then likely the problem was a manufacturing/design flaw.