Inspection + common appliances

If you are concerned about the boiler then just tell them up front that you need to see it. Make sure that you give them ample time so that someone is available on the day of the inspection to give you access.
I don't know at what point you are at in your negotiation, but tell the Seller that the inspector MUST see certain things otherwise you won't buy. Then let them be the ones to pressure the managing agent. Also try to get roof access if possible.
The brokers will probably tell you that you can't get access and that this is how it is done in nyc, but they're just trying to make the deal go quicker and make things easier for themselves.
We likely would have run into the same problem seeng the boiler where we are buying but our unit has its own heating system in the unit which we had acess to.

We had access to the boiler and roof for inspection. There was also information about the roof in the minutes.

i know that at my old building, they had 3-4 inspections over 6 years that i was there and the inspector had access to everything. the super was notified 4-6 business days in advance about the inspection.

Also, if you go to the DoB website, www.nyc.gov/buildings. On the righthand side of the screen you can enter the building address and see any permits, violations etc are on the property. There is a tab that specifically addresses boilers. If the building is over 6 stories, you can also check to see the status of the last Local LAw 11 facade inspection. Talk about another repair that can break the bank!