One thing worth noting... SKY charges for repairs/callouts to fix problems whereas Virgin is always free and usually very fast. Worth checking with your new provider if they do the same.
I think you are wrong mate, same roules apply as with any other ISP, specially if it involves a BT visit: line faults, exchange/dsl service faults - free. I had engineers come in twice in the last 4 years with sky, no charges.
If it's your internal equipment at fault and BT is sent out for a visit - then you get charged for the visit £200-300 I think. Internal equipment: microfilters, switches, cables (phone/network). Generally I think you need to think as your kit the stuff from the wall/BT socket. If it's the VDSL/ADSL boxes - they count as their kit.
Some will try to claim that the face that goes on top of the master socket is your kit also, but they won't press if you argue that it says BT on the box so it's the ISP/BT kit.
To be safe fallow the normal DSL troubleshooting steps (it applies to fibre to some extent) or call the ISP and they will walk you thought the same steps:
- Reset router
- Reset router but leave for 20 mins
- Confirm ADSL light is on permanently after 30-60 secs
- Make call from line through microfilter
- Dial 17070 and then option 2 for a 'quiet line test' to see if there is noise on the line
- Works?
- Call quality OK?
- Call 151 for BT Faults if line is noisy or faulty
- Make sure nothing else is connected to any extension and test from master socket (BT socket inside if NTE5 master socket )
- Try new router (with up to date firmware) + microfilter and any other cables
- ISP line test
- BT visit