England's Ashes glory was confirmed when the third Test at Old Trafford was abandoned due to rain yesterday, leaving them 2-0 up against Australia in the series.
"There are no extravagant celebrations," BBC Sport quotes Flower as saying.
"We want to win the series. We are only three matches into a five-match series and are 2-0 up, so we want to win at Durham."
The penultimate Test begins on Friday.