Place the potatoes in Dutch oven or large saucepan; cover with water.
Bring to a boil.
Reduce heat; cover and simmer for 25-30 min. or until tender.
Drain and rinse in cold water.
Refrigerate until cooled; cut potatoes into 1/4 in. slices.
In large skillet, cook bacon over medium heat until crisp; remove to paper towels.
Drain, reserving 4 Tbls drippings.
In the drippings, saute the onion until tender.
Stir in the flour, salt, celery seed, and pepper until blended.
Gradually add the sugar, vinegar and water.
Bring to a boil over med./high heat; cook and stir for 2 min or until thickened.
Reduce heat to low.
Add the potatoes and bacon; stir gently.
Sprinkle with parsley.