The bedroom measures 2.12m/2.51 (part of the wall is recessed) by 3.41m. It used to be the porter’s bedroom so it is a like-for-like replacement. The boiler is hidden in the corner by the door but could be easily relocated. You’ll need listed building consent as you’ll need to punch a hole in an external wall to accommodate the flue. This shouldn’t be an issue so long as the flue is on any of the north-east facing walls. You’re unlikely to be granted permission to locate it on the south-west facing walls as these overlook the cloister.
Alternatively, you could convert the bedroom (and bathroom) into a kitchen and dining area.