Apex domains cannot have CNAME records.
Question and response
Question
dig redstation.co.uk. NS
Answer
redstation.co.uk. 3 NS heracles.iomart.com.
redstation.co.uk. 3 NS iphicles.iomart.com.
redstation.co.uk. 3 NS hebe.iomart.com.
Authority
The response has no authority records.
Additional
hebe.iomart.com. 3 A 74.117.184.100
heracles.iomart.com. 3 A 62.128.193.135
iphicles.iomart.com. 3 A 84.22.161.172
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0