Heat the water in a large pot until it simmers.
Add diced potatoes; simmer for 10-15 mins until tender. Drain and set aside.
In a big bowl, mix potatoes, eggs, onion, celery, mayo, mustard, vinegar, paprika, sugar, salt, and pepper.
If desired, include chopped dill; gently toss.
Taste and adjust seasoning if needed.
Refrigerate for at least one hour to blend flavors.
Enjoy chilled or at room temperature.