In his early career, Summers worked as a runner and then later assistant director on films such as The Dam Busters (1955) with Michael Anderson and Moby Dick (1956) with John Huston.

In 1969, still under contract with ITC, Summers directed a number of episodes of the popular series Randall and Hopkirk (Deceased), working with actors Mike Pratt, Kenneth Cope and Annette Andre.

Other directing credits include Jason King (1971–72), Boy Dominic (1974), and Return of the Saint (1978, this version with Ian Ogilvy cast as Simon Templar).

In the 1990s he directed many episodes of the television soap operas Coronation Street, Emmerdale and Brookside (including the film spin offs The Lost Weekend, Friday the 13th and Double Take!)

While on Brookside, he also directed the Liverpool FC feature The Last night of the Kop commemorating the final time the football stand was used before Anfield became an all-seater stadium.