In a large pot, combine chicken, water, vinegar, onion and salt and bring to a boil. Reduce temperature to medium and keep soup cooking at a gentle boil for 1 hour with lid on and slightly uncovered.
Remove any scum that has formed on surface of soup. Add carrot, parsnip and celery and continue cooking for another hour.
Add parsley and dill and continue cooking for 30 more minutes.
Remove chicken from pot and separate meat from bones. Set aside to serve in the soup, or save for a later time.
Be sure to remove any metal/plastic tags from chicken before cooking.
The purpose of the vinegar is to draw calcium and other minerals out of the bones, making an even more nutritious soup.
For best results, allow for 2.5 hours of cooking time.