Slow Cooker Sloppy Joes

Ingredients

• 1 1/2 pounds ground beef
• 1 cup chopped onion
• 1 cup chopped green bell pepper
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1/4 teaspoon garlic powder
• 1/4 teaspoon paprika
• 1/4 teaspoon celery seed
• 1 (8 ounce) can tomato sauce
• 1/3 cup ketchup
• 2 tablespoons packed light brown sugar
• 1 tablespoon Worcestershire sauce
• 1 tablespoon apple cider vinegar
• 1 tablespoon Dijon mustard
• 1/4 cup water
• Hamburger buns