Unable to Connect HP Printer to New Gateway XB8-T

Less than a month ago, I decided to rent a Gateway device instead of buying my own modem/router device which I had been doing for years. Three days ago, a technician came to investigate intermittent internet connection issues that had been going on for THREE months. Along with fixing a line issue, he changed out the Gateway device. I have no clue why since the issue predated the device, but I guess he was covering all his bases. My HP Envy 4500 series printer no longer connects wirelessly to the network. I've spent hours on the phone with tech support with no resolution. Any ideas? I have no idea which model I had for a couple of weeks before this one. I wish I had logged the model of the old one, so I could exchange this new one for the old model.