The quickest way to reset your Comcast modem
A reset clears your modem's memory and restarts its connection to Comcast's network. Most connection problems—slow speeds, dropped internet, pages that won't load—stop after a reset. You have two options: a soft reset (restart) that takes 3 minutes, or a factory reset that erases all settings and takes 10 minutes. Start with the soft reset unless Comcast support tells you otherwise.
The soft reset is what you want most of the time. It powers the modem off and back on without erasing anything. A factory reset wipes out custom settings and should only happen if the soft reset fails or if support specifically asks for it.
Key Takeaways
- A soft reset takes 3 minutes: unplug the modem, wait 30 seconds, plug it back in, and wait for the lights to stabilize.
- A factory reset erases all settings and requires holding the reset button for 10 to 15 seconds—only do this if a soft reset does not work.
- After either reset, your modem needs 2 to 5 minutes to reconnect to Comcast's network before you test your internet.
- If the modem still will not connect after a factory reset, contact Comcast support with your modem's serial number and account number ready.
How to do a soft reset (the restart method)
Unplug the power cable from the back of the modem. Wait a full 30 seconds—this clears the modem's memory. Then plug the power cable back in. The modem will start up, and you will see lights begin to flash on the front panel.
Watch the lights on the front of the modem. You will see a power light (usually white or blue), an internet light, and lights for each connected device. When the internet light stops blinking and stays solid, the modem has reconnected to Comcast's network. This usually takes 2 to 5 minutes. Do not unplug it again during this time.
Once the internet light is solid, test your connection by opening a web browser and visiting any website. If the page loads, the reset worked. If you still have no connection, wait another minute and try again—sometimes the reconnection takes longer on the first attempt.
How to do a factory reset (the button method)
A factory reset erases every setting on the modem and returns it to the state it left the factory. Only do this if a soft reset did not fix your problem, or if Comcast support asks you to. After a factory reset, you will need to set up your modem again from the beginning.
Locate the small reset button on the back of the modem. It is usually recessed (pushed in slightly) so you cannot press it by accident. Use a straightened paperclip or the tip of a ballpoint pen to press and hold the button for 10 to 15 seconds. You may see lights flash or go dark—this is normal. Keep holding the button until the lights begin to flash again, then release.
The modem will restart and go through its startup sequence. This takes 5 to 10 minutes. The internet light will blink while it reconnects. Once the internet light turns solid, the factory reset is complete. Your modem is now back to factory settings and ready to be set up again if needed.
What the lights mean during a reset
The front panel of a Comcast modem has several lights that tell you what is happening. The power light (usually white or blue) should be solid when the modem is on. If it is off or blinking, the modem is not getting power or is having a startup problem.
The internet light (often labeled "Online" or shown as a globe icon) is the most important one. When it is solid, your modem is connected to Comcast's network. When it is blinking, the modem is trying to connect. If it stays off or red after 5 minutes, the modem cannot reach Comcast's network—try the soft reset again or contact support.
Lights for individual devices (often labeled "Link" or "Ethernet") show whether computers or other equipment plugged into the modem are connected. These do not affect whether your internet works, but they tell you if a cable is loose or a device is powered off.
Common mistakes that prevent a reset from working
The most common mistake is not waiting long enough. After you unplug the modem, wait the full 30 seconds before plugging it back in. If you plug it back in after 5 or 10 seconds, the reset may not clear the modem's memory completely. Set a timer on your phone if you are not sure.
Another mistake is testing your internet too soon. The modem needs 2 to 5 minutes to reconnect to Comcast's network after a soft reset, and up to 10 minutes after a factory reset. If you test after 30 seconds and see no connection, wait longer instead of unplugging it again. Unplugging it while it is reconnecting can interrupt the process and make it take even longer.
If you do a factory reset, do not panic if you lose your internet for a few minutes. The modem is erasing its settings and restarting—this is supposed to happen. If the internet light does not turn solid after 10 minutes, then you have a real problem and should contact Comcast.
When to contact Comcast support instead of resetting
If the soft reset does not fix your problem after two attempts, contact Comcast support before trying a factory reset. Have your account number and the modem's serial number ready—you can find the serial number on a sticker on the back or bottom of the modem. Support can check whether there is a problem on Comcast's end that a reset will not fix.
If the modem will not power on at all, check that the power cable is plugged into both the modem and the wall outlet. Try a different outlet in case the first one is broken. If the modem still will not power on, the power supply may be faulty and you may need a replacement modem from Comcast.
If you do a factory reset and the modem reconnects but you still have no internet, the problem may be with your account or Comcast's network in your area. Contact support and explain that you have already done a factory reset—this tells them the modem itself is working.
Frequently Asked Questions
Will a reset erase my passwords or saved settings?
A soft reset will not erase anything—it just restarts the modem like restarting a computer. A factory reset erases all settings stored on the modem itself, but it does not affect passwords saved on your computer or phone. You may need to reconnect devices to your Wi-Fi after a factory reset.
How often should I reset my modem?
You should only reset your modem when you have a connection problem. Resetting it regularly is not necessary and will not improve your speed. If you need to reset more than once a month, contact Comcast support—it may mean there is a deeper problem with your service or equipment.
What is the difference between resetting the modem and resetting the router?
A modem connects you to Comcast's network. A router (sometimes built into the modem) distributes that connection to your devices wirelessly. If you have Wi-Fi problems but your modem lights show a good connection, reset the router instead. If you have no internet at all, reset the modem first.
Can I reset my modem while someone is using the internet?
You can, but they will lose their connection during the reset. The soft reset takes 3 minutes total, so internet will be down for that time. It is polite to warn anyone in your home before you unplug the modem.
What if my modem does not have a reset button?
Older Comcast modems may not have a reset button on the outside. If you cannot find one, a soft reset (unplugging and plugging back in) is your only option. If that does not work, contact Comcast support—they may send you a replacement modem.