Dunkirk gas steam boiler keeps going off (sometimes 3 times in one day).?

Each time my heat goes off I go to the basement and refill the gl tube to ABOVE the water level. Sometimes the heat turns off 3 times in one day. My landlord says he KNOWS what the problem is and has been trying to fix it himself, but obviously he DOESN'T know. Time to call an HVAC person myself.