Why Is My Apple Watch ECG Not Working? What to Check First

Updated on October 27, 2026

This article contains affiliate links: if you buy through them, Wanda-techs earns a commission at no extra cost to you.

When the ECG on your Apple Watch isn’t working, the app is missing, won’t finish setup, or gives you a result you can’t use. The usual causes are the watch model, your country, a pending update, or a watch worn too loosely. Check these points in the order below.

Common symptoms and causes

The ECG (electrocardiogram) records the electrical activity of your heart for 30 seconds.

• ECG app missing from the watch: unsupported model (SE, Series 3 or older), unsupported country, setup not done in the Health app, app not installed on the watch.
• Setup won’t complete: iOS or watchOS out of date, user under 22, unsupported region.
• Recording interrupted, “Inconclusive” or “Poor Recording”: watch too loose, arms not resting, dirty or wet skin or watch, wrong wrist set in the settings, movement, electrical device nearby, heart rate between 100 and 120 BPM, implanted pacemaker or defibrillator.

Good to know: depending on its version, the app shows “Sinus Rhythm”, “Atrial Fibrillation”, “Low or High Heart Rate”, “Inconclusive” (version 1) or “Poor Recording” (version 2).

Before you start

Keep the iPhone paired with the watch within reach.

Warning: the ECG on your watch does not replace a doctor. It only detects sinus rhythm and atrial fibrillation, not a heart attack, a blood clot, a stroke, high blood pressure, heart failure or other arrhythmias. If you have chest pain or other signs of a heart attack, call 911 (112 in Europe) right away.

Warning: solution 4 ends with a re-pairing, which erases the contents of the watch. Back up your iPhone first. The watch data is restored from that backup, but a small amount of data may still be lost.

Solution 1: check the model, the updates and the country

1. Check that your watch is an Apple Watch Series 4 or later, or an Apple Watch Ultra: the SE, the Series 3 and older models don’t have the ECG app.
2. Update the iPhone to the latest version of iOS.
3. Update the watch to the latest version of watchOS.
4. Open the watchOS feature availability page and check that your country or region is listed for the ECG app.
5. Check that the user is 22 or older: the ECG app is not designed for people under 22.

If everything checks out, the ECG app can be set up. Go to solution 2.

Apple keeps the list of countries up to date on its watchOS feature availability page. The United States, the United Kingdom, Canada, France, Belgium, Switzerland and Italy are on it.

Good to know: Apple gives no minimum version number. Install the latest version offered, on both the iPhone and the watch.

If your watch is an SE or a Series 3, it will never get the ECG app. Here are two recent Apple Watch models that have it.

Solution 2: ECG app not found, set it up and reinstall it

1. Open the Health app on the iPhone and follow the ECG setup prompt if it appears.
2. If it doesn’t, tap Browse > Heart > Electrocardiograms (ECG) > Set Up ECG App and follow the screens.
3. If the ECG app doesn’t show up on the watch, open the Watch app on the iPhone and tap Heart.
4. In the ECG section, tap Install.
5. Open the ECG app on the watch.

The ECG app icon appears on the watch. The app opens on the recording screen.

Tip: no ECG section in the Heart menu? Go back over the checks in solution 1 before going further.

Solution 3: make a proper recording

1. In the Watch app on the iPhone, open My Watch > General > Watch Orientation and check which wrist is selected.
2. Wear the watch on that wrist.
3. Clean and dry your wrist and the back of the watch.
4. Tighten the band so the back of the watch touches your skin.
5. Move away from plugged-in electrical devices.
6. Rest your arms on a table or on your lap and relax them.
7. Open the ECG app on the watch.
8. Rest a finger of your other hand on the Digital Crown, without pressing.
9. Stay still for the full 30 seconds of the recording.
10. At the end, add your symptoms if needed, then save the ECG.

The recording runs the full 30 seconds and shows a result, for example “Sinus Rhythm”.

Tip: sit at a table with your forearms flat. It is the surest position for staying still and relaxed for 30 seconds.

Good to know: with version 1 of the app, a watch worn too loosely or arms that aren’t resting can give an “Inconclusive” result.

Solution 4: restart, update, then re-pair the watch

Apple’s ECG page doesn’t describe restarting or re-pairing. These are general troubleshooting steps. If pairing itself is stuck, see our guide to “unable to communicate with Apple Watch”.

Warning: step 4 erases the contents of the watch. Make sure a recent iPhone backup exists before you unpair.

1. Turn the Apple Watch off, then on again.
2. Restart the iPhone.
3. Check again for an iOS and watchOS update and install it.
4. As a last resort, unpair the watch in the Watch app, then pair it again and restore it from the backup.
5. Set up the ECG app again from the Health app.

If nothing works

Contact Apple Support if the ECG app stays missing or every recording fails. This applies to a watch that is compatible, up to date, set up and worn correctly. For other faults, see our guide to common Apple Watch Series problems, or the one on a watch stuck on the Apple logo.

Warning: if you have chest pain, shortness of breath or feel faint, don’t wait for the watch result. Call 911 or 112.

Protect your iPhone and Apple Watch: our selection

These accessories secure the iPhone’s backup and power before an update or a re-pairing.

Frequently asked questions

Why isn’t the ECG app showing up on my Apple Watch?

The ECG app only appears on a compatible watch, in a country where Apple offers it, once it has been set up from the iPhone’s Health app. The Apple Watch SE, the Series 3 and older models don’t have it. If your watch is compatible, install the app from the Watch app on the iPhone, under Heart, with the Install button.

Does the Apple Watch SE have ECG?

No, no Apple Watch SE has the ECG app. It is limited to the Apple Watch Series 4 and later and all Apple Watch Ultra models.

What does an inconclusive ECG mean?

An “Inconclusive” result means the app couldn’t classify the recording as sinus rhythm or atrial fibrillation. Apple lists these causes: a heart rate between 100 and 120 BPM without atrial fibrillation, an implanted pacemaker or defibrillator, another arrhythmia, a signal too weak in some people, or a loose watch and arms that aren’t resting. Record again using the method in solution 3.

How do I turn on ECG on the Apple Watch?

You turn on ECG from the iPhone, in the Health app, by tapping Set Up ECG App. If the prompt doesn’t appear, go to Browse > Heart > Electrocardiograms (ECG). Then open the ECG app on the watch to make a first recording.