In large bowl, place beans; add enough water to cover beans by 2 inches. Soak 8 hours; drain.
Spray 5-quart slow cooker with cooking spray. In 10-inch skillet, cook sausage and vegetables over medium heat 4 minutes, stirring frequently, until sausage is browned and vegetables are tender. Add garlic; cook 1 minute longer. Drain. Place beans and sausage mixture in slow cooker. Stir in broth, water, salt, thyme and red pepper.
Cover; cook on Low heat setting 8 hours.
Stir rice into soup. Cover; cook 10 minutes longer or until rice is tender. Garnish individual servings with thyme sprigs.