BT have connected 8Mb ADSL to new phone line. I went in and installed a Draytek router.
It is installed as a router not a bridge like the other two ADSL lines.

20th Nov, CX reported a problem. WAN1 had been disconnected due to dogey ADSL line. The Draytek router showed WAN3 and WAN4 had been automatically disconnected. The test to check the line was up was to ping www.bbc.co.uk
It has stopped responding to pings. Changed pings to check www.batchworth.org lines came back up.