Steibel Eltron heater sparking while off

Hi,

In my home I have 4 Steible Eltron heaters. All work apart from the one in my bedroom. I had an electrician in over a week ago who managed to get it working for a day. The night It was fixed it was turned off before I went to bed and the next day it wasn’t working again at all. The electrician told me that the element in it had burnt out but now I am being woken up during the night because it is sparking and a loud noise appears. It has happened twice that I know about. The switch to power the heater has been off so I don’t understand how it can spark? I’m worried that it will be happening when I am out of the house and may cause a fire? I am currently 7 months pregnant so would like to know that everything is safe? On a separate note when I turn the other heaters on/off at the switch there appears to be a green spark behind the plug when they’re turned on/off.  Anyone got advice?  Thanks 

Can you un plug it or remove the fuse? 

There should be a connection unit somewhere? 

As for the green sparks on sockets? It's down to cheap plastic being slightly translucent. When you switch a heavy load like a heater it will sometimes arc.

I have a BG usb socket in my living room and Mrs Duck decided to plug the Iron (2kw) in and when she saw the spark from the switch she was worried it doesn't happen with the other sockets as they are old MK, made of better plastic from days of yonder.

Where for art thou Katie? 

I can take the fuse out! Will that mean it’s safe? Any ideas why it’s happening?

Thanks for your help