I've always kept our boa's a bit cooler than the BP's and provided a very deep substrate for them as they do seem to enjoy burrowing. He may well be stressed. I assume you bought this snake from a reputable vendor so hopefully health is not an issue but quarantining him completely from any other snakes you own is always a smart thing.

You might want to place a light weight but dark in color material over his enclosure leaving a bit open for ventilation. Something like a dark pillowcase or light sheet often seems to help our boa's settle in better especially if they are in a busier part of the house. Even our male whose been with us since he was a tiny thing has a black sheet over part of his big glass tank to allow him some privacy and downtime from being seen (he lives in our livingroom which is a busy part of the house). He also has a huge black plastic hide which he often uses.