New Gas Steam Heating Burner

<span>This past summer i had my oil burner replaced with a gas burner In a 3 story row building.  What i have noticed that on the top floor in the bathroom i hear the air escaping from the # D air valve, and hear the steam rising, however the radiator does not get warm. It seems that the Thermostat that's located on the second floor reaches it temperature before the steam can rise into that radiator, can you help me with this?</span> <span>Also my living room radiator on the top floor does not get hot all the way, just seems to get hot half way?  </span><span>I keep the thermostat set at 73 degrees, but when i bump it up to 78 (just to see what happens) Then all the radiators on the top floor get hot. </span> <span>Thank you for your time </span> Brooklyn