On a dry system, the technician usually starts with the thermostat and power, then checks ignition, flame sensing, and safety switches, and on oil equipment the nozzle, filter, and fuel line. After flooding, expect a slower look at every part the water touched; controls and gas valves that sat in salt water are commonly replaced rather than dried out.
If the fix turns into a replacement, permits follow. Hull's gas and electrical permits can be filed online, but the part-time gas inspectors set their own inspection times, and the Building Department is closed on Fridays. Ask how the contractor plans to keep the house warm in the meantime.
Older Hull homes can hide surprises such as an unlined chimney or corroded piping, so a contractor may recommend more than the immediate fix. Ask which items are urgent and which can wait for a separate written quote.