electric space heaters suck a TON of power. if there is anything else plugged into the same fuse that uses much power at all it will likely blow the fuse. i used to have an electric space heater in my herp room and i moved it to a different plug in the room, which apparently was on the same fuse as a fan i had in the bedroom nextdoor. i turned on the fan and fuse blown, every time.

ditch the electric heater and get the oil filled one. you shouldn't have a problem with it blowing the fuse.