Force Restart the Watch
Hold the side button and the Digital Crown together for 10 seconds. The side button is the flat one below the Digital Crown on the right side. Keep holding even after the logo disappears or flickers, a full 10 seconds is key. The watch should restart and boot normally.
If it makes it past the logo, you're set. That was a one-time boot hang. If it loops back to the logo, move on to the next step.
Let It Charge for 30 Minutes
A nearly dead battery can keep the watch from finishing the boot sequence. It tries to start, runs out of power, and tries again. Place the Ultra 3 on its magnetic charging puck for at least 30 minutes. The Ultra 3 supports fast charge, 0 to 80% in about 60 minutes, so half an hour gives you plenty of headroom.
After 30 minutes, try the force restart again (side button + Digital Crown, 10 seconds).
Unpair the Watch in the Watch App
If force restart and charging don't get you past the logo, the next step is to unpair the watch through the Watch app on your iPhone running iOS 26 or later. Unpairing erases all data on the watch that hasn't synced to the phone, unsynced workout or sleep data from the last sync will be lost. Health data already in the Health app on your iPhone is safe.
Open the Watch app, tap All Watches at the top, then tap the info icon (i) next to your Ultra 3. Tap Unpair Apple Watch and confirm. The iPhone backs up what it can and then wipes the watch. This takes about 5 to 10 minutes. Once the reset finishes, set the watch up from scratch. If the watch was already deep in a boot loop and not connecting to the phone, the unpair command may fail. In that case, try the direct reset method below.
Reset Directly on the Watch If It Boots Briefly
If the watch shows the logo and then manages to reach the watch face or setup screen for even a few seconds, you can reset it from the watch itself. Swipe to open Settings > General > Reset > Erase All Content and Settings. Enter your passcode if prompted and confirm.
After the reset, the watch boots to the pairing screen. Open the Watch app on your iPhone and follow the setup prompts. This clears whatever app or setting was hanging the boot.
When the Watch Is Briefly Connected
Sometimes the watch connects to the iPhone for a moment between boot loop attempts. If you see it show up as connected in the Watch app, you can trigger a remote reset quickly. Go to All Watches > tap the info icon next to your Ultra 3 > Unpair Apple Watch. The phone sends the reset command over Bluetooth. It only works if the connection holds at the exact moment you tap, which is hit or miss, but it's worth a shot before the next method.
If the Logo Still Won't Go Away
If none of these steps get you past the Apple logo, the watch likely needs a firmware restore that only Apple's tools can do. Apple doesn't offer a public reflash tool for watchOS the way you can with an iPhone via a Mac. The watch will need to go to an Apple Store or be sent in for service.
Before you do that, double-check you've tried force restart, charging for at least 30 minutes, unpairing through the Watch app, and a direct reset on the watch. If it's still looping after a clean unpair and reset, it's a hardware-level firmware issue or a failing storage chip, not something you can fix at home.
