Garmin 810 showing totally incorrect grade + elevation on ride in the rain?

Has anyone else encountered this problem. I did a ride today that I did a month ago and it registered a 1000ft less in elevation gain. 600ft instead of 1600ft. It was also showing totally wrong gradient figures on climbs. One climb is ~ 10% and it was registering < 1%

Keen to hear from others whether they are prone to this in wet weather.

Happens to my 510.

My 800 did this a while ago. There is a barometric pressure sensor hole that I suspect when wet stops the real air pressure being sensed, hence it shows less altitude. The only solution is to keep the unit drier (maybe used one of those silicon covers or something).

Yeah fairly common I think, I’ve read about it before. The pressure sensor gets water in and it messes it up.

I think mine showed 600ft on Tuesday instead of the normal 1400+

as above, just means some moisture got into the hole for the sensor

Missed Large’s post, silicon covers don’t work either. You need to use elevation correction in Garmin connect, you’re stuck in strava though I think

Nah there’s elevation correction in Strava too

Really? Swish, better craft on and get my badge

My 510 over reads nearly all the time.. about +20%

Water blocks holes on barometer sensor so the air pressure recording isn’t accurate and the unit believes that rather than the GPS altitude (or occasionally flips between the two).

A silicon case makes a big difference in my experience, mine hardly ever misreads now unless its really wet for a prolonged period. Strava elevation correction is available on desktop version – click the m ascent and it’s an option there, not sure you can do it from the app.

It happened with my 705, 800 & still does with my 810. The silicon cover helps in all but the heaviest rain.
Edit: It even happened with my old eTrex Vista, water blocks the barometric sensor hole.

use to happen to me all the yime i use a money bag loosely fitted in the rain
wotks a treat counts feet as normal . put garmin in the bag before you switch it on and it finds gps signal and your current location
no probs

Cheers all. I think that’s a unanimous “it’s not faulty” conclusion. Which was my main concern. Pretty naff though.

The breather hole is pretty exposed on the 810, on the 1000 it was relocated under the mount:

Air pressure goes up and down all the time – so by measuring altitude by air pressure wont it go up and down as well ?

Don’t you have to calibrate it first at a known height for a given air pressure ?

Don’t you have to calibrate it first at a known height for a given air pressure ?

Garmin devices with barometric sensors calibrate themselves (given time) it can take half an hour or more sometimes. You can also set you start/s point elevation and as long as you press start within 30/40 feet of that location/s it will calibrate your elevation to that point/s.