This fireplace had a gas fire with back boiler. I don't want a fire anymore, going to make it tidy and put a houseplant in there or something.
Where the equipment was originally installed they must have taken a lot of brickwork out of the right hand side to do it. All there is now is the single skin of bricks at the front, and on the right side they've loosely piled in bricks and cemented them, which doesn't look to me like it'd bear a lot of load.
The opening was reduced. I chipped away to reveal the extent of the original concrete lintel, and below that there's some bricks stuffed in loosely, cemented, and flat steel lintel at the bottom to support that, which seems fine i suppose.
https://imgur.com/a/lPv7sVq