Good news - BG heating engineers turned up more-or-less on time and made a lot of banging and clattering and assure me that the wailing banshee has been removed from the boiler.
Meanwhile, ADSL issues....
Call to ISP to provide update (system works if I use the test socket in the BT master socket). They say it's then a domestic wiring issue - even if that is to replace the (BT) master socket. BT call out, inclusive of one hour's labour is a very generous GBP150
So, go to my local high street where there are two electrical goods shops (both local firms) both have electrical contracting arms. They say - hang on, I'll chat to our chaps. Hands me the phone and I have a chat. His view (they are licensed to install telecoms equipment) is the the master socket is extremely unlikely to be the issue - more likely to be a) faulty micro-filter (GBP7), b) problems with a Sky box connection, c) faulty phone d) faulty socket, e) faulty cabling. Recommended a systematic check through before booking an appointment. If they do come out it's GBP45 for first hour plus parts.
So, I reconnect router to main socket and disconnect both phones and sky boxes.ADSL works - so it is NOT the master socket that has failed.
Connect lounge micro-filter. Still working. Connect lounge phone. Still working. Connect Sky box - not working.
So it's either the very lengthy cable between the sky box and the socket (about 30 ft and before you think I live in Tenor Viol Palazzio, the cabling goes around the door frame, so there's 15 ft
) or it's the Sky box.
So, it's a big
to the local electrical retailer for both saving me an extortionate BT fee and good advice.
I now just need to work out if it's the cable or the Sky box - that won't be an easy one to determine.