Note that Onkyo's have been reported to tend to run a bit hot too.
@bs1979
Can you help to tell us, how hot? My general rule is to place my hand on the top of the chassis. If it gets to be so hot that I cannot keep my hand on there for an extended time, then there is a problem. However, if I can easily keep my hand on there for 30 seconds or so, then there is no problem.
With that being said, I have also noticed that my Denon 4400 tends to run a bit on the hot side. But, my hand test says, no problem. What I find even more interesting/odd is that my 3500 does not seem to run nearly as hot as my 4400, even if I'm running the same speakers at relatively same levels. But, I'm not sure if the comparison is fair, because the 3500 is in a smaller room and has a little better ventilation. The 4400 ventilation is fine, just not quite as open as the 3500.
It should also be noted that I do not activate Eco mode on either system.