I've got an HRM4 paired with my 5x and it's generally pretty well-behaved. The exception is when I'm on the treadmill doing intervals. My watch is consistently within 2 or 3 BPM of the HRM on the treadmill while I'm walking, then when I start to run the Fenix jumps to 250, give or take, and stays there. Even when I slow back to a walk it stays at 247-250. The HRM on the treadmill shows me back down around 135 but my 5x is still showing 250 for the remainder of the run. I've adjusted the strap to make sure it's damp underneath and I'm religious about rinsing it daily and taking it into the shower with soap every few days. Thoughts?
Is this is the older button-snap style HRM-RUN with the little dude and the replaceable strap?
If so it's dying. Mine did the same thing -- it started the same way, but it would eventually cut it out after 20-30 minutes into a workout. Then it did it routinely and every time. I tossed it eventually and bought a new one -- problem disappeared.
It's NOT the battery -- I replaced mine with a known good, brand new battery -- no change.
These things fail in this sort of way and when they do they screw up your data for a *long* time too, as that bad data is in Connect and there's no way to get rid of it that I know of.
I had the snap-on version and put it away somewhere safe when I got my fenix 5 and updated to the red one, never to be seen again. It certainly has occurred to me that it would be cool to see if I got similar readings from it.
These straps do benefit from some tender loving care. And that begins with following the care instructions. If you have been diligent with that then, as noted above, chances are the strap's conductivity has been compromised. You're in luck if yours is the one with the snap-on module as the bands are readily available and cheap. If not, then it's a costly replacement.
Well, I've never put it the washer, rinsed it every time I used it and took it into the shower with me once a week or so. I also changed the battery when this started happening. But bottom line is that SOMETHING is wrong, so I'm not discounting anybody's theories here. I just hate to spend a hundred bucks to see whether the same issue remains.
You might also want to try replacing the battery in the HRM, if you haven't already tried this. Sometimes when the battery is low you can start to see some unusual readings.
Welp, I just replaced the battery again and the next 24 hours will tell.
If you still have the other button-snap style one, and it's still working, use that for a bit and see if the problem disappears.
It's almost-certainly not the strap part -- when mine did it I replaced the strap part with a new Polar strap (which fits perfectly) without improvement, and also changed the battery (although it was not indicating it was low on the watch, and it DOES report a low battery -- I had previously gotten a warning six months or so prior and had changed it then.)
My suspicion is that the seals on the electronics to the strap portion, over time, let a small amount of salty moisture (e.g. sweat) through and then it's just a matter of time before something bad gets bridged, and whatever is most-susceptible to that causes this specific sort of fault.
If you still have the other button-snap style one, and it's still working, use that for a bit and see if the problem disappears.
It's almost-certainly not the strap part -- when mine did it I replaced the strap part with a new Polar strap (which fits perfectly) without improvement, and also changed the battery (although it was not indicating it was low on the watch, and it DOES report a low battery -- I had previously gotten a warning six months or so prior and had changed it then.)
My suspicion is that the seals on the electronics to the strap portion, over time, let a small amount of salty moisture (e.g. sweat) through and then it's just a matter of time before something bad gets bridged, and whatever is most-susceptible to that causes this specific sort of fault.
Yeah, looking at it more closely it looks like there's a little delamination on one corner of one of the electrodes. You may have a point.
