Wondering if anyone else has found a problem with the optical heart rate sensors of Garmin watches in which the plastic warps, making the sensor inoperable. I have now owned three different watches (Vivoactive HR, 735 & 935) which have all had the same problem.
My major issue is with Garmin’s failure to recognize this as a design / cheap material issue. I’ve been told three times now that this is only covered under the limited 90-day warrant and that I would have to pay $150 to have the defective unit replaced with a refurbished one.
I have a 735XT and the optical sensor is similarly damaged. It looks to me like it was cracked though, not warped. I assumed I had just been careless with the watch sometime when it was off my wrist though, never bothered to contact Garmin about it. I’m out of warranty anyways.
I have this odd curved thing on my 735 sensor too. You can definitely feel it. I first noticed it last summer after pretty much daily use for one year. So far it seems to be functioning ok though. Will follow this thread.
That’s exactly what I thought happened to my first watch, the Vivoactive. I thought I just was careless and broke it. Then I got the 735 and noticed the same type crack in the sensor after about 3 months. Knowing I was much more careful with it, I watched it and took pictures over the course of about 3 months as it continued to wear and warp, until it stopped working. That’s when I contacted Garmin and was told it would be $150 to get it fixed/replaced. When I bought my 935, I was very careful with it. After six months I noticed the same wear/warping damage to it, which was just last week. I’m keeping track of how it progresses.
I do live in AZ, where it is very hot and dry. I’m wondering if that might have anything to do with it. I wonder if people living in moist climates are not experiencing this.
My first Garmin 735 had the exact same cracking issue with the led HR sensors and I paid $150 because I was afraid of water leaking into the watch. With my replacement 735, I now remove the watch upon entering a hot tub, steam room, or sauna - no cracks have appeared. The watches also had a circular piece of plastic (sticker) over the sensors which easily wore off on both watches. This problem has been going on for a while and Garmin should either fix it or remove the sensor since I use the HR strap when running (to get running data) or riding (to connect with my 510) anyways. See link to Garmin site: https://forums.garmin.com/forum/on-the-trail/wrist-worn/fenix-3-hr/135836-small-cracks-in-hr-sensor
A little follow-up. Today I called Garmin to discuss this issue. They have “opened a case” into this design/materials issue. Specifically they are looking into possible chemical interactions that would cause the plastic to warp and crack. The important thing, they are replacing any devices free of charge that display this defect. They will require a picture of the damage emailed to them and then have a series of questions for you to answer about what chemicals you use on your body or that come in contact with the watch.
Vivoactive HR owner for almost two years. Wear it all the time except when it’s charging. Swimming, biking, running, working, sleeping, etc. No issues to date!
Looks to me like a stress cracking problem. Did you have exposure to alcohole based subsatnces?
All transparent plastics tend to stress cracking in contact to certain chemicals.
The Garmin optical hart rate sensor window only has limited alcohole resistance.
I’ve been wearing a Garmin OHR watch nearly 24/7 for 2+ years now - ever since the 235 came out in Oct/Nov 2015. Briefly also wore a 735 and am currently using a 935. No issues whatsoever for me.