Extremely newbie question! I'm looking to remove a redundant electric fireplace heater - it's wired into a switched fused spur on the wall, which won't be used again after the heater's removed. The spur is always switched off, and I don't want to remove the actual box it's housed in. Both ingoing & outgoing cables are your standard mains three-wire ones, like with lights and appliances.
I know to turn off the power etc before touching anything in there, but is it safe to unscrew the outgoing wires (the ones connected to the heater) and keep the ingoing wires screwed in? As long as it's always switched off?
(Equally, would it be dangerous if it ever got switched on? It seems like this should work on the same principle as a normal plug socket, but I want to make sure!)
Or if that isn't safe, what's the best way to disconnect and isolate the ingoing wires while keeping them all inside the box?