Remodelling fireplace

ILoveSittingDown

Yeah we've seen loads that we love, just need to do the sums before I get out the crowbar, sledgehammer and power chisel combo

FreeBear

An excuse to go out and buy an SDS drill with some long breaker chisels

I have a really long chisel (originally for something like a Kango) - Came in very handy for digging out the rubble infill behind my fireplace. I suspect your opening can be made much larger without too much effort. If there is a register plate above your stove, it may be possible to lift it so that a camera can be shoved in. Something like the image below - A very handy gadget to have...

Poke around above the register plate, and you may well find there is a lot of space either side, and above. You might even be able to spot the lintel (or arch) inside.

Be warned - You will make loads of mess, so put down plenty of dust sheets. You'll also get a tonne (literally) of rubble out.

TVs, and any other electronic equipment, shouldn't be hung over a stove. The rising heat will kill them fairly quick. When I have my stove going, I'll regularly see wall temperatures in excess of 150°C (got sensors embedded in the wall, hooked up to a data logger). At those sorts of temperatures, regular gypsum plaster will fail. You need to use a heat resistant plaster (e.g. Vitcas), or a lime plaster.

ILoveSittingDown

I've got one of those cameras but unfortunately can't lift the plate above the log burner to have a look