Gosh, I am sorry, but I have found those things, AC/heating, plumbing, to be such an expense in a single family home, If the other people in your building in your home are not doing proper maintenance that is going to affect your equipment.I'm glad you are asking all these questions because I didn't even think of them. In the paperwork I did today there was a request for the condo HOA info. They have (I think) 10 days to get that to me, then I have (I think) two weeks to read it all and decide if I want to back out of the purchase if I don't like something.
But I never even thought about the plumbing pipes (tho I did run each faucet and flush the toilet). I'm pretty sure I'm responsible for the furnace. And I'm sure I'm responsible for the electric bill because I remember the realtor saying the only utility bills I would have were electric and phone (HOA provides water, sewer, trash, cable tv, and high speed internet).
I don't know where the air conditioning comes from, I think it is on the roof of the building, I don't know whether the equipment is separate for each apartment, it was warm the day I looked at the apartment and I turned the thermostat down to check how noisy it might be and the furnace fan was very quiet but the air coming out of the vent was super cold (nice). I'm guessing the building provides the hot water, there is so much I don't know! Oh deary me.
example, if they are pouring grease down the kitchen sink that will effect everyone, if they are not changing the filters on the heating and AC units, that will affect eveyone, if they are are putting things in the garbage disposal that do not belong there, that will affect everyone.