Expect the technician to start with safety: checking for gas leaks, testing for carbon monoxide, and looking at venting before restoring heat. In older Marshfield houses, which make up a large share of the town, they may also look at the chimney liner or flue, since many heating problems start where exhaust leaves the house.
After a coastal storm, a careful contractor will ask how high the water came and whether it was salt water. They may recommend replacing controls, a burner, or a whole unit that was submerged rather than restarting it, and the same storm may affect several homes on your street at once.
If the emergency fix becomes a replacement, a permit follows. Gas equipment goes through the Building Department's online system with its Plumbing and Gas Inspector, and oil equipment goes through the Fire Department's application and inspection.