Not to worry found this old 2006 post on this site
http://www.diynot.com/forums/viewtopic.php?t=66799
No marking on my connection post but the wires are colour coded
Problem sorted
Cheers
Our new Bosch electric double oven that arrived today has no + or - marking on the two insulated connectors in the back of the oven only a earth connector marking.
The old Creda oven had markings but being AC i'm sure it is not important which way they are connected. Am I right?
Thanks...