ok wtf do I do, I'm pretty sure I've fucked badly. Need to replace the valve in a toilet cistern, the locking nut is completely fused to both the pipe and the actual cistern (combination of hard water, being decades old and the fuckwits who lnstalled it painting over it)

>tried a wrench, couldn't get enough grip to budge it
>screwdriver and hammer wouldn't budge it
>resorted to trying to destroy it with drills and heated screwdriver tip, won't budge even after multiple sections are gone.

This is in an extremely tight spot in a corner, I've limited access to it which contributed to me fucking up so badly. What do I do now?

>>2932414 (OP)
Locking nut? So the black one that holds the filler into the tank?
They are normally plastic aren't they? Heated screwdriver tip? Lol. Uh for me if you can't drill the nut gadget a screwdriver in to split it then it's a junior hacksaw, start on the threaded tail cut diagonally up though the nut.
But honestly I don't know why you can't gust get big pair of water pump pliers over that and show it a good time. It's fucking plastic dude come on. Maybe psych yourself up a little and try one more time.

>>2932423
No adjustable wrenchs or basin pliers go over it. It's too flat, too large and the plastic is too soft. Any attempt just falls off.

I've just had a go at it with a jr hacksaw and... Nothing. Pretty sure I've gone all the way to the ceramic, cutting as close as possible to pipe. Nothing fell off, no sign of any loosening. I tried drilling but the bit was sliding all over the place and given I have to drill way too close to my face because of how little space there is (see pic), fuck that

The entire thing is simply fused to both the pipe and ceramic

Channel locks.

Cut it and replace the thread if you need to. Disassemble the toilet and fix or replace it.

>>2932432
The thread there is actually PVC from the existing valve (they painted over everything ), that will be going no matter what but I'm worried if I was to cut through that to get at the nut vertically, I'd never get the tiny bit left in the pipe out.

Think I'm going to have to go out tomorrow and try and find the sharpest chisel available...

Fuck yeah. Got that piece of shit off.

Actually ended up being easier to undo the bottom bolt than I thought it'd be, undid that, sawed off the bottom of the PVC theading, then sawed down the middle of the bolt. Was then able to use a hammer and chisel where the bolt met the ceraamic and that warped it enough to lift a bit of it out the hole. Then went all the way around the top through the gap that was created with the chisel and hammer until it eventually popped out.

Getting the new valve in was trivial (thought I might struggle to get it in as the idiots who were responsible for that fused locking bolt also connected the drainage and water at the wrong ends). I now have a working toilet without an overflowing cistern!

>>2932596
nice one. worried when i read chisel thinking itl end up cracking the cistern glad to hear you got it out not too much trouble lol. fucking hate toilets always disgusting shit everywhere.