Echo had learned that Boyd was in the same apartment building as her; a lot of people that she knew were in that building. So was Alpha. Having Claire in the next room and Boyd a few doors away made her feel safe, as well as the fact that she could protect herself against Alpha. With Boyd knowing the truth she felt easier knowing that she didn't have to pretend to him.
She'd made the decision to go to him, wanting to see how he was getting used to this place and to inform him of anything if she could. She gave a gentle tapping onto the door, calling out a quick 'hello' before waiting. She hadn't seen him yet other than talking to him on the network, so seeing how he was now since he was from the future would be interesting.