Erich was the son of Karl Hermann Waschneck, a blacksmith, and his wife Therese Emilie, née Schneider. Waschneck went to finishing school at the Leipzig Art Academy and studied painting.
He came in contact with the film industry in 1907 when he began to paint posters for films. He then worked as a still photographer and later as a camera assistant to cinematographer Fritz Arno Wagner .
In 1921, he did his first work as a cameraman in the adaptation of the fairy tale The Little Muck by Wilhelm Hauff. From 1924 he worked as a director. His film Eight Girls in a boat (1932) won the Gold Medal at the Venice Film Festival. In 1932 he became managing director of Beacon-Film GmbH in Berlin and film producer. After the Nazi rise to power, into force on 4th Waschneck April 1933 the National Socialist Factory Cell Organization German-born film directors with.  In 1940, he directed the anti-Semitic propaganda film The Rothschilds'.
After the war Waschneck was only able to direct two films.
- The Pearl of the Orient (1921)
- A Glass of Water (1923)
- The New Land (1924)
- The Stolen Professor (1924)
- My Friend the Chauffeur (1926)
- The Man in the Fire (1926)
- The Woman with the World Record (1927)
- Aftermath (1927)
- Sajenko the Soviet (1928)
- Docks of Hamburg (1928)
- Scandal in Baden-Baden (1929)
- Favorite of Schonbrunn (1929)
- Diane (1929)
- Two People (1930)
- Sacred Waters (1932)
- Eight Girls in a Boat (1932)
- Hände aus dem Dunkel (1933)
- Abenteuer im Südexpress (1934)
- Music in the Blood (1934)
- Regine (1935)
- Mein Leben für Maria Isabell (1935)
- Liebesleute - Hermann und Dorothea von Heute (1935), awarded: "artistically valuable"
- Uncle Bräsig (1936)
- Escapade (1936)
- Gewitterflug zu Claudia (1937)
- The Divine Jetta (1937)
- Anna Favetti (1938)
- Women for Golden Hill (1938)
- Kennwort Machin (1939)
- The Rothschilds (1940)
- Between Hamburg and Haiti (1940)
- Die Affäre Rödern (1944)
- Three Days of Fear (1952)
- Have Sunshine in Your Heart (1953)