Treacy, who joined Burnley this week from Preston, was shown the door at Ewood Park in January 2010, and it left a bitter taste.
He said: "I never had a chance at Blackburn. The managers changed so quickly I never got my foot in the door.
"I want to get Burnley back to the Premier League, play against Blackburn and ram it back down their throats."
The 22-year-old Irish international added: "I have a bit of vengeance in mind for Blackburn. I am at the right club for it anyway!"