Phone over ethernet over powerlines?

[MrRobin]

Why are you plugging in your Sky box in the first place?

Sky insist that the box has access to a phone line so it can phone home periodically. The installation engineer won't do the work if there's no access to a line. Once he's completed it and he's gone, you can just unplug it and it will still work just fine.

I would suggest you buy a £1.99 extension lead, let the guy install the box where you want and connect it to the lead that you can just trail accross your living room floor, and then when he's gone just pack it all up.