Apple Watch Series 8 ECG not working since software update it seems

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Apple Watch Series 8 ECG not working since software update it seems

My Apple Watch Series 8 ECG consistently starts but never gets past 29 seconds. It immediately resets to the 30-second starting screen. The ECG worked normally on June 27. I'm running watchOS 26.6, iOS 26.6, and ECG version 2.23U67. I've restarted both devices, my previous ECG recordings are still in Health, and the electrical heart sensor works normally." This is also happening to a friend of mine as well. Same exact issue which leads me to believe something is wrong since the last update.

Apple Watch Series 8, watchOS 26

Posted on Aug 18, 2026 12:52 PM

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Answer 1

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WheelieNick

Level 9

55,415 points

Aug 18, 2026 1:34 PM in response to MARISARTO

When an Apple Watch ECG freezes and resets right before finishing at 29 seconds, it is usually caused by a micro-interruption in electrical contact, background signal noise, or a persistent software glitch following an update.

Advanced Troubleshooting Steps

Reinstall the ECG App: Delete the ECG app directly from your Apple Watch, restart the watch, and reinstall it via the Watch app on your iPhone under the Heart section.
Clean the Contacts: Clean the back crystal sensor and the Digital Crown with a slightly damp, lint-free cloth to remove invisible oils or residue.
Check Posture and Stability: Rest your arm and hand flat on a table, use the index finger of the opposite hand with very light, steady contact on the crown, and avoid any muscle tension or movement.
Unpair and Re-pair: Unpair your Apple Watch from your iPhone to create a fresh backup and clear out corrupt cache data tied to the health app syncing protocols.

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