Hello andrewkk; this is Onkyo USA’s Product Support Dept. and we would like to thank you for your purchase and for posting your concern. As our receivers do require high current to drive that awesome sound you enjoy- a byproduct is residual temperature.
Our receivers do tend to run about 80 degrees above ambient room temperature, this is normal. If you install the apparatus in a built-in installation, such as a bookcase or rack, ensure that there is adequate ventilation. Leave 20 cm (8") of free space at the top and sides and 10 cm (4") at the rear. The rear edge of the shelf or board above the apparatus shall be set 10 cm (4") away from the rear panel or wall, creating a flue-like gap for warm air to escape. Please make sure that when you turn off the main receiver that you also turn off the Zone 2 because if you don’t turn off Zone2 (if your receiver has this feature) then the receiver will continue to run and will produce heat. There is an internet dealer selling cooling fans that can be used with our receivers www.coolerguys.com.
If you have any more questions or concerns, Please contact our Product Support Dept for further assistance with this specific issue via our phone number and hours of operation (800-229-1687; option #3 PRODUCT SUPPORT 24 hours a day). We would assist and answer any questions or concerns you may have with your Onkyo product, as we are also available via email firstname.lastname@example.org.