User profile for user: InsafA
InsafA Author
User level: Level 1
12 points

Heart rate sensor inactive for all functions except ECG on Apple Watch after watchOS update

Hello,

I'm facing a serious issue after updating my Apple Watch to the latest firmware version (presumably related to iOS 18.6.1). The watch has completely stopped measuring my heart rate, both in the background and during workouts. As a result, the active calorie counter shows "0" for any physical activity.

I have already tried all the standard and advanced troubleshooting methods recommended on forums and by Apple Support, but none of them have resolved the issue:

  • Force restarting both the iPhone and the Apple Watch.
  • Checking all privacy and health settings, including permissions for heart rate data and fitness tracking.
  • Disabling Power Saving Mode for workouts.
  • Resetting my fitness calibration data, followed by a 20-minute outdoor calibration walk/run.
  • Completely unpairing the Apple Watch, allowing my iPhone to create a backup, and then restoring the watch from that backup.

Despite all these actions, the problem persists. The heart rate sensor is not functioning, which renders the watch's fitness features useless.

Since this problem appeared immediately after the update, I have strong reason to believe it is a software bug in the new version of watchOS. I urge the community and Apple's engineering team to investigate this matter. Is anyone else experiencing similar issues, and are there any other potential solutions? It seems a patch may be required to fix this.





I've confirmed that the heart rate sensor on my Apple Watch is physically working, but only when I run the ECG app. It successfully records my heart rate during the ECG test.

However, for all other functions, the sensor fails. When I try to take a manual reading using the Heart Rate app or a watch face complication, it just displays the 'Measuring...' message indefinitely without ever providing a result.

The sensor also remains completely inactive during background monitoring and does not turn on for any workout sessions, which is why my workouts continue to log zero active calories.

This behavior makes it very clear that this is a software bug, not a hardware failure. The latest watchOS update seems to have broken the connection between the heart rate sensor and all apps/services except for the ECG app.

I hope these specific details help the engineering team to diagnose and resolve the issue in a future update.


[Re-Titled by Moderator]

Original Title: 've confirmed that the heart rate sensor on my Apple Watch is physically working, but only when I run the ECG app. It successfully records my heart rate during the ECG test. However, for all other functions, the sensor fails. When I try to take a ma

Apple Watch Series 10

Posted on Aug 17, 2025 12:31 AM

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20 replies
User profile for user: LD150
LD150
User level: Level 10
99,499 points

Nov 16, 2025 4:26 PM in response to InsafA

InsafA wrote:

• ..
• Completely unpairing the Apple Watch, allowing my iPhone to create a backup, and then restoring the watch from that backup.…..

….…..

you omitted the most powerful diagnostics & Reset action


Unpair then pair again without use of a backup. Ie As New Watch


You really don’t lose much, just saved faces and alarms in my experience.

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User profile for user: Markmarkmark25
Markmarkmark25
User level: Level 1
14 points

Oct 5, 2025 11:46 AM in response to pgershon

Updated to 26.0.2 last night, and still same problem.

  • Heart monitor does not capture data (no green dots on back of watch)
  • Peloton bike connectivity fails 100% -- doesn't work with Peloton bike (although you see it trying; no green lights)
  • Peloton app connectivity occasionally works (when connecting for a walk, green lights capture HR sometimes)


This is same as 26 but was hoping 0.2. patch would improve. Sadly does not.


Am going to make Genius bar appt for replacement.

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User profile for user: Markmarkmark25
Markmarkmark25
User level: Level 1
14 points

Nov 20, 2025 3:31 PM in response to Markmarkmark25

btw, i went to genius bar and they did full diagnostics. unsurprisingly, no issues on hardware. they're going to send it in for repair, but not sure what would come from it.


not sure if this helps for anyone's pattern matching, but if i start the day and go outside and just start the heart rate monitor, it works maybe 50% of the time (green sensor lights activate, and i get a reading). same success rate as ecg and workout. peloton app works less often.


but if i start the day trying to use my peloton bike, the bike will detect the watch and heart rate monitor, but the watch's green light sensors never activate (98% of the time). after that, no heart-rate activity will work on any app in any circumstance (at least for the rest of the day) regardless of what hardware or device i am or am not connected to.


so it's not a peloton hardware issue, but there is some element that once "stuck' remains stuck.


i've done full reset/wipe of the watch, uninstall/install, new id, clean everything. removed all apps and reinstalled, etc. all the suggestions on ancient watch threads of revoking/granting permissions, bluetooth, motion detection, privacy, blah blah.


nothing works.


just pushed it to a friend inside apple to see if it can better visibility for help.


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Heart rate sensor inactive for all functions except ECG on Apple Watch after watchOS update

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