Wifi router is not working

WiFi will appear on a phone, computer, etc. regardless of whether you have an internet connection.  That just means the phone, computer, etc. can talk to the modem.  The blinking yellow and red lights sound like the modem isn't connecting to Comcast's system.  It's probably either a Comcast problem or a building problem.  In the larger buildings I've lived in the cable company brings service into a room in the basement and past that the wiring is the apartment building's responsibility.

You may need to get a tech out to reconnect the other end of the line to the live Comcast feed. Many times it is disconnected when a prior tenant moves out. You may likely also need to get the modem activated for service. Good luck !

@user_fc0bc0 Hello and thank you for taking the time to create this post for our Xfintiy Community Forums! You have reached the right place for help. I am sorry to read about the trouble connecting to the internet after moving to your new place - I know that can be very stressful. 

Do you have a personal modem or an Xfinity Gateway? Did you activate the equipment when setting up in your new home? Here are two incredibly helpful support articles to walk you through activating either type of device:

Xfinity Gateway: https://comca.st/3yoICLE

Your Modem: https://comca.st/3yrOvYi

Please let me know if you are still unable to connect after activating your equipment and we can go from there!

@XfinityElizabethA 

FWIW. They stated that the indicator lights are blinking. That indicates that the modem has not established block synch with the system. If there are no problems with the connectivity / communication to the system, a modem will obtain block synch regardless of whether or not it has yet been activated / provisioned for service. Meaning that the *Online* indicator light would be steadily lit, not blinking.