boiler cleaning & lay-up

ross

My mother lives in a 17 unit housing complex that is heated a gas-fired forced combustion cast iron steam boiler. They don't have a boiler guy on the premises, just a maintenance person who blows the boiler down periodically. At the end of spring they shut down the boiler. What type of lay-up practice would you recommend? Currently they just shut it down until the Fall. Every Fall they have a boiler contractor open it up to be fully cleaned and inspected, which costs a couple thousand bucks. Is this type of maintenance necessary every year, or is it overkill? On the one hand, it seems maybe a bit excessive. On the other hand, this is the one time a year that a knowledgeable boiler contractor looks at it. What do you guys typically do?