Job done today!! That little black box thing was a bit on the fiddly side to shift out of the way to get to the 3rd thermostat bolt!!
I also decided not to undo the plugs inside it!! would've been much easier if i had undone them though but didn't want to upset anything!! lol
Gave the rad a right good flush out with the hosepipe. TBH looking at the coolant & lack of crappy bits in the drained fluid it looks like it was changed not that long ago!! anyways, doesn't matter, now got new theromstat & a system full of Comma Xstream longlife red antifreeze
Next job on the list is gearbox oil!! Got some Fuchs Titan Sintopoid 75w90 sat here waiting to go in!!