residential, one and two family houses, or commercial , is there a difference? Are there different codes for them? this is a regular room, Hot water tanks are there, and the heating system are there, nothing else.
All things, therefore, that you want men to do to you, you also must likewise do to them
BTU capacity, operating pressure of the system, and things of that nature have an impact on needing emergency stop switches at the entrance(s) to the room for some boilers. I don't know those codes - but when the boiler installers say they are needed they tell me exactly where to place them - as they are the ones that get the correction notice if it isn't right. Lighting - NEC is reasonably silent here also. You will probably find you do need illumination but it doesn't have anything on how much illumination is necessary, that would have to come from other codes if there is a requirement.