Garmin 5x plus Altimeter after 10.00

In the past week I have noticed that the altimeter on my watch has been off severely. I will check it in the morning and nothing it is off by 400+feet. I manually calibrate it to what I know about my location. 

I check it again when I get home from work and it is again off by 400+ feet. I will reset it again before bed and go to sleep. I wake up in the morning and once again it way off. I have ran the water over the sensor to clean out and debris. 

Is there a fix for this? Or will I have to send it back in for a new watch?

ETA: I noticed that my watch updated itself to 10.00. I thought I had these off. I am now convinced that the 10.00 update screwed up my altimeter. 

Thanks. 

  • Does it always revert to the same altitude during night?

    The watch will in the default configuration attempt an automatic altimeter calibration during sleep if connected to a phone. It will ask the phone for coordinates (it will not use its own GPS), and then it will look up the coordinates in the internal DEM map to find the map altitude for those coordinates. This altitude will be used to calibrate the altimeter.

    So one explanation could be that the DEM map for your location is wrong. Another explanation could be that you are sleeping 400 feet below ground level, but I guess that is not likely. There are probably plenty more possible explanations.

    You could try to disable the nightly calibration and see if it makes a difference. At least you can the be sure that the nightly calibration is the culprit. But it will not necessarily bring you closer to a solution.

  • It does it any time of the day. I took it off a few hours ago to charge it. I reset it manually back to my current elevation and put it on the charger. It has lost 200ft of elevation in that time. 

  • Then I would first check the Ambient Pressure measurement. This is the actual pressure being measured by the watch, without any altitude correction.

    (The other pressure, Barometric Pressure, is altitude corrected, so you can't use that for troubleshooting altimeter problems.)

    You can check Ambient Pressure in two ways:
    1. Configure a data field in an activity to show Ambient Pressure. This is one of the standard choices, so you don't have to download anything. But you have to be in an activity to see the pressure.

    2. Download a widget showing Ambient Pressure. There are several of those.

    When you have a way to see Ambient Pressure, you need to find something to compare it to. If you have your own weather station, which can show barometric pressure, that is fine. Otherwise you can go online and find a weather station or airfield near to where you live.

    When comparing the Ambient Pressure in the watch to the data from the weather station, you may see a difference. This is not necessarily a problem. It can be caused by an altitude difference between you and the weather station, or it can be caused by the weather station showing the pressure converted to sea level pressure.

    What does matter is that the difference between the watch and the weather station should stay constant. If the difference is +5 millibar right now, it should not be +15 millibar tomorrow. If the difference varies over time, then you may have a hardware problem.