EXHAUST FAN – COMMON OR PRIVATE?

My neighbour has a problem with the executive committee. On the advice of the  strata manager, it has ruled that the heavy duty exhaust fan which ventilates three areas – a bathroom, laundry and toilet by drawing ducted air and discharges it outside the building is private, not common property and therefore the owner’s responsibility to service. The fan and motor are in a sealed unit mounted in-line in the 12″ ducting. The unit is suspended from the underside of the floor slab of the unit above, at the moment only visible through a cut-out in the top of a kitchen cupboard. It is therefore behind and slightly above the long boxing that runs over the kitchen cupboards and the separate cooktop exhaust fan. One of the problems is its inaccessibility, due to the developer not allowing an access port in the boxing. However, as it is in the ceiling space, connected to ducting which runs in the ceiling space, we cannot understand how it can be defined as the owner’s property and responsibility. Has there been a ruling on this sort of problem, are there precedents that can be searched? What reasons could be put forward that justify the committee’s ruling?