Why Is My Deco Stuck Flashing Red?

You're staring at your Deco unit, and it shows flashing Red light on it. And no matter what you try unplug it, wait, and hope, but it just keeps flashing. You did the setup, followed the instructions. Maybe it was working fine yesterday.

Let's learn about what's going on here and most importantly, how to fix it.

What Does the Flashing Red Light Mean?

First, let's break down what the red light actually means.

If your Deco is flashing red, it's usually because:

• It can't connect to the Internet

• The main Deco unit has lost its link to the modem

• There's a firmware problem

• It's stuck during setup

• Or it tried to reboot and never fully recovered

Put simply: The Deco isn't setup and it's stuck trying to get online or complete its startup.

Step 1: Check the Modem First

The Deco doesn't make the internet - it amplifies it. So if your modem isn't giving it a signal, the Deco will keep flashing red until it finds something to work with.

Here's what to do:

• Unplug your modem and wait 30 seconds

• Plug it back in and let it fully reboot (wait for the light to stabilize)

• Now, unplug the Deco, wait 10 seconds, and plug it back in

• Give it a few minutes.

If the problem with the Deco flashing red goes away and the light turns green or white, you're fine. If not, continue.

Step 2: Check the line and port for the Ethernet cable

• Unplug the Ethernet wire that connects your main Deco to the modem and then plug it back in firmly on both ends.

• If you have another cable, try that one too.

• • Make sure it's put into the right port on both the modem and the Deco. This port should say "Internet" or "WAN."
  • The Deco will flash red every once in a while because wires are too loose or twisted.

• . It's amazing how often one small thing can solve the whole issue.

Step 3: Restart the whole network.

If a simple power reset doesn't help, try restarting everything in this order:

• Turn off the modem

• Turn off the Deco

• Wait one minute

• First, turn on the connection and wait until it fully starts up.

• After that, turn on the Deco

Time is important sometimes. When the power is on, the Deco needs to connect to the modem. If the modem is not ready, the Deco can't connect and gets stuck.

Step 4: Open the Deco App

Start up the Deco app on your phone
Check to see if the Deco is visible. If it says "offline" or "disconnected," that means it can't connect to the internet. Tap on the Deco icon to see any problem messages or connection information.
The app will sometimes give you more hints. It tells you where to look next if it says "No Internet" or "Cable turned off."

Step 5: Try a Factory Reset

If your Deco has been flashing red for a long time—like 10+ minutes—and nothing is changing, it might be stuck. A full reset can help.

To do it:

1. Find the reset button on the bottom or back of the Deco

2. Use a paperclip or pin to press and hold it for 10 seconds

3. Release it when the LED starts blinking yellow (that means it’s resetting)

Once it resets, open the Deco app and go through the setup process again. Make sure your modem is fully online before starting.

This is also a good chance to double-check that your ISP hasn’t changed anything—like new login settings or MAC address filters.

Step 6: Update Firmware (If You Get It Working Again)

Once you’re back online, go to the Deco app:

• Tap More

• Tap Update Deco

• If there’s a firmware update, install it

Sometimes that red flashing issue is linked to a bug that’s already been patched—but your system hasn’t been updated yet.

When to Call Support

If your Deco flashing red problem keeps coming back, or if the reset doesn’t fix it, it might be a hardware issue. It’s rare, but it happens.

Check if your Deco is still under warranty. TP-Link support can usually walk you through advanced troubleshooting, and they’re good about replacing units that are truly faulty.

Final Thoughts

That Deco flashing red light is a signal that something’s gone wrong between your mesh and your modem. It doesn’t always mean something’s broken—but it does mean something needs attention.

Start with the basics. Check the modem. Reseat the cable. Reboot things in the right order. And if nothing works, reset and start fresh.

Once the Deco gets reconnected properly, it usually runs smooth. Fast speeds, solid range, no drops. You just have to get past that red light first.