Help me with my new hottools curl iron?

i recently bought the jumbo hot tools curl iron because i have super long hair (up to my waist) and ive heard that hot tools is one of the best curlers there is. So this is my 2nd time attempting to make a curl but unfortunetly it doesnt curl! i let it heat for like 5 minutes and when doing a curl i count up to 15- 30 seconds but nothing happens it stay flat. (i used to use a bedhead curl iron and this never happen! it would curl but it just wouldnt last all day) so now what should i do to make this curl iron work? any ideas please?