1) In a slow cooker, soak beans in water overnight.
2) Do not drain the water.
4) Put the lid on and cook over high heat for 2 to 3 hours, until tender.
5) Stir in carrots, celery, onions and seasonings.
6) Put the lid on and simmer for 10 to 12 hours.
7) Stir in the frankfurters before the last 30 minutes of cooking.
8) Press some for the bean with ladle and mash to thicken the soup.
9) Serve the soup hot garnished with fresh parsley.