I just spend a week in Valencia at Ivan & Carmina´s place. Its located right in the old district of "Carmen" with a lot of bars, cafe´s and restaurants. Its within easy walking distance to all the main sights and also very close to the Turia Gardens. There are supermarkets within walking distance, too. Its an old building with a very narrow and steep staircase so make sure you don´t take any heavy luggage!!! I just had hand-luggage and a small backpack so I was fine.
Also in case you are a light-sleeper make sure you bring ear-plugs with you because there is a bar right across the building with people sitting or standing outside most nights.
I met Ivan twice I think and he was super friendly and he and his wife were always answering emails very fast- Thank you for a great week in beautiful Valencia!!!!