Following from Will's comment, can it connect directly to your TV with an HDMI lead, without bothering with aerial or internet connections? Worth a try.
On planet BT, I've had a similar issue when upgrading our BT boxes over the years, and had recordings on the redundant box that we wanted to keep. Recorded material can't be tansferred or converted to an accessible format on another storage medium, not even another box of the same type, something to do with both the file format and the OS software in the BT boxes. The BT system will only recognise one box at a time connected to the outside world via internet/aerial, (well, it is sort of possible, but only by throwing money at BT) but simply connecting our old box to the TV via HDMI still allowed access to the recorded programmes. In effect it was a bit like an "access only" external hard drive on a computer. We couldn't use the box to record or watch live TV, but we didn't need it for that anyway.
(BT ask for the old boxes back, but I've never done that. Once they've served their purpose, I've taken the hard drives out, formatted them, and use for additional storage on my computer. You can never have enough terabytes.)
(If you haven't got enough HDMI sockets on your TV, to avoid having to plug/unplug each time, there are multi adapters widely and cheaply available.)
Any Sky boffins out there?