Add the carrots, celery, onion, and split peas to a large soup pot. Add 8 cups of water and stir. Bring to a boil and reduce to a simmer. Cover and cook for 30 minutes. Remove lid and add in the liquid smoke, salt and pepper. Simmer for 10 more minutes.
Turn off the heat and allow the soup to cool slightly. Blend the soup, in batches if needed, until smooth. Return to the bowl to heat up to your desired serving temperature. Serve as is or top with croutons and pimenton.