Place chicken breasts in a 6-quart slow cooker. Add chicken broth, black pepper, crushed red pepper, and garlic powder.
Cover slow cooker and cook on LOW for 5 to 6 hours.
Shred the chicken and add the pasta, Ranch dressing mix, cream cheese, water and half the cheddar cheese. Stir to mix and press pasta down into the liquid.
Cover and cook on HIGH for 30 to 40 minutes, stirring after 20 minutes.
Sprinkle the remaining cheddar, bacon, and green onions on top. Place lid back on and let sit 5 minutes. Serve.