Cut potatoes in to bite size pieces and boil in pot of lightly salted water. In a large pot cook bacon and set aside when browned, do not drain grease. In same pot cook until tender onions, carrots, celery, salt, pepper and garlic salt.
Drain clams and reserve the juice in a bowl, add clams to pot and cook until heated. Add butter, milk and parsley and cook until heated stirring often. Add the flour to the reserved clam juice and stir to remove any lumps. Add mixture the the pot and stir until thickened. Add more salt and pepper to taste.