i have 4 Aaon rooftops on top of a hotel in Naples. And two of witch have no charge i spent all day Friday looking for leaks. units are 2 year old i put 200psi of nitro and 1lb of 410 as a trace gas after spending 2 hrs looking for the leaks with my crap tech mate leak detector and my psi dropping 5psi. I went out and got a fieldpiece leak detector witch cost me $305 come back and find leaks in my reheat coil valve on both units. After calling around a rebuild kit is $407 my valve $420 i need 2 and 65lb of 410. so this week i strongly dislike Aaon.
Those step valves aren't real easy to braze in the way they're mounted at the side of the unit.
We had an L series class in the shop and they brought a trailer in with an RTU to let us look at it and see it run. I was new and I asked "did you guys copy an aaon?" they did not think it was funny.
We see a wide range of Aaon unit types and ages. Their old stuff is good and the new stuff is built like the old stuff. A lot of times when I work on them i find my self asking "why doesn't anyone else do it like this?" those units were old too. Things seem easier to get to, coils seem more robust and most of the time are slanted, hinged doors and latches with hardware to hold it open, slide out blower assembly's, gear drive economisers, etc etc. I am mostly talking about general RTU from small to 50t. Not every Aaon is great like the liebert wannabes we see. I have changed a lot of parts out on RTUs and for the most part they seem a little smoother than most. In our shop the most grumbling I hear is startup issues and bell and whistle overload.