I have not got a Hornby Elite unit but I would imagine it either has the capability to read the address, configuration variable (the dreaded CV) 0; or if not to write a CV to the locomotive
If it can not read then program CV 0 to what number you want it to be and it will overwrite whatever is there.
If the locomotives are brand new then the address will be 03 to start off with.
If it can not read then program CV 0 to what number you want it to be and it will overwrite whatever is there.
If the locomotives are brand new then the address will be 03 to start off with.