How hot should a McCormack DNA-225 get?

I recently picked up a 6 year old one that was just factory checked. The heat sinks get pretty hot with no signal, and with music at moderate levels (feeding Infinity 8 Kappas, nominally 6 ohms) for half an hour, get almost too hot to touch! I'll call the factory and ask, but thought a voice of user experience could be more "honest." It is on a bottom shelf of a cabinet with open front and large openings in the back. At the time nothing was above it (over 2 feet of air.) The DNA-225 is replacing my 20 year old Adcom GFA-555 which would only get "hot" after a good while of cranking out some tunes.

Also, in a different room, the amp is tripping a 15-amp circuit breaker at turn on. Nothing else is on at the time. The original location may have been on a 20-amp circuit, I'll have to check.

Both these things make me wonder if the factory missed something. Ticket said they just biased some transistors. Any owner expeiences would be greatly appreciated.

Thanks,

Mike