Typical start-up sequence: Thermostat calls for heat, induced draft fan starts, delay, hot surface igniter glows, burners fire and once heat exchanger achieves temperature the blower fan starts…
On a transitional style furnace (w/draft fan & mono port burners but standing pilot), I have seen two now that had no delay between draft fan, burners and blower. Is this typical?
My first though would be no its not normal but would have to see what kind of fan control was installed is it bi-metal or control board is there a pressure switch to prove out positive draft fan