25+ yr old boiler in my apartment?

just moved into an apartment here in anchorage, upon meeting my neighbors I was informed the previous tenants moved out due to excessively high heating costs because the 'long over due' boiler. The broker told me that the boiler is an older one but works just fine and passed some kind of certification saying it was in good working order. The broker also told me that since its older our heating will run a bit more than the other units by about $20 a month. Which didn't sound so bad, but my neighbors now have me worried that the gas bill is going to be $200+ dollars (2 bed 1.5 bath 1100ish sqft) a quote given to them by the previous tenants. What can I do about this? Is there anything I can do? I know that ak landlords are required to provide heat equipment such as boilers in a good and safe working order, but what constitutes good? Is economical a figuring factor? I could understand $100 in the winter for this unit (heated 1 car garage) but $200 or more? I think that is outrageous, what should the price be? How would I get them to replace the boiler?