During his early career as an actor he came to public notice playing PC Francis "Taffy" Edwards in The Bill between 1983 and 1990.

In addition there were public readings of some seventy five plays by authors as diverse as Hannah Cowley and John le Planché, Since 2012 he has resumed a freelance career as well as being the Artistic Director of The Production Exchange, a charity that encompasses an artists’ agency, production company, and mentoring service working across all creative media.

Under the pseudonym of Daniel O'Brien he is a prolific writer of work for the stage and his pantomime scripts have been performed annually in a number of theatres notably at The Riverfront Arts Centre in Newport, Wales, Sutton Coldfield Town Hall and the Theatre Royal, Wakefield.

He has also recorded two video commentaries for The Bill Podcast Patreon Channel, where he was also reunited with eight of his Sun Hill co-stars for a three-part Zoom reunion.

Blumenau has more recently returned to screen acting, featuring in the Blumhouse horror You Should Have Left, and guest-starring in an episode of EastEnders.