When they changed my box for a 4010, which has no pass through, I made the engineer split the cable (again) so that one went into the box and the other went to my video (and then to the telly).
I had to get the engineer to do this as our aerial on the roof is unwatchable (crap signal), but the engineer did it, well after I offered chocolate biccys with his tea!
I get 8 or 9 analogue channels (including sky 1) and my didgy box on the telly but only the normal analog channels on my video (something to do with the telly having a European tuner).
He was already in the house for a fault, but I guess they would charge you if you wanted them out just to split the cable (wink wink)