Fitbit is contacting some owners of its Sense smartwatch to offer replacements after discovering a bug affecting its electrocardiogram (ECG) readings. Users on the Fitbit forums have reported receiving emails from the company, warning that their devices are affected by an unspecified “hardware issue.”
Fitbit has subsequently confirmed to The Verge that the issue specifically affects its ECG functionality, and that less than 900 devices globally are affected. The emails ask affected users to return the smartwatch to Fitbit and says they will be given a replacement device free of charge.
Along with stress detection and temperature tracking, the Fitbit Sense’s ECG app is one of its major differentiating features compared to Fitbit’s other recent smartwatch; the Versa 3. The ECG feature is meant to allow the watch to read the wearer’s heart rhythm for problems like atrial fibrillation. Although it wasn’t available when we reviewed the smartwatch back in September, Fitbit rolled out its ECG app the following month.
When contacted for comment, a Fitbit UK spokesperson confirmed the issue to The Verge, and said that the problem affects the ECG app on a limited number of Sense devices. The problem means the app can incorrectly display an “inconclusive” result during readings. Fitbit has also confirmed that no other devices, or future Sense smartwatches shipments, are affected by the issue and said it is contacting affected users directly to issue replacements.
The $329.95 Fitbit Sense has had a bit of a rough launch. Some of its most impressive features weren’t available in time for our review, and what was left could be buggy to use. But so far Fitbit has shown it’s willing to address these issues. It’s released updates to add new features like the ECG app and support for Google Assistant, and now it’s proactively replacing devices with faulty hardware. In our review we said Fitbit needed to take some time to work out the Sense’s kinks, and it appears to be doing just that.
Update December 4th, 12:12PM ET: Updated with Fitbit’s confirmation that less than 900 devices worldwide are affected.