Is there a do it yourself laundry near the old section of Valencia, or better yet, a laundry where we can
drop our clothes off in the morning to be washed and dried and pick them up in the afternoon.? I know some cities have such places.
Your best source for this type of information is your hotel's front desk. They live there.
I was in Valencia last fall and needed to have some laundry done - I had been traveling for about 15 days at that time. I asked at the front desk of my hotel and they recommended the department store El Corte Ingles. I took my clothes to them one afternoon and got them back about 24 hours later.