@KrispPL The working temperature is 0-50 Celsius, so it's running a little hot. Is there anything that could be causing that in your network environment? 

Is this a relatively new device, or has it been running for a good amount of time? 

  @KrispPL I see you're on the pre-release firmware; if you revert to the latest stable firmware, can you see if the issue persists? 

Hi  @KrispPL 

Thanks for reaching out to TP-Link Business Forums.

Upon checking, the OC300 can run under the temperature below: Specifications - OC300 | Omada Hardware Controller | Omada by TP-Link

Hence, it's indeed now running in a relatively high temperature.

Can you help check the ambient temperature and whether the installation environment is poorly ventilated?

Did you configure any advanced setup?

  @Gabriel-TP 

In taking a look at this, my OC300 V1.0 always has a CPU temperature of around 56°C. The router-controller combination is mounted in an under-desk mount as shown below.

The ambient temperature is currently around 25°C and the warmest point on the OC300 underside measures 42°C.  The underside is warm to the touch but not what I would consider hot,  Everything has been working perfectly since the installation and I believe that I read somewhere that the CPU temperature in the mid 50's was normal.

The ER7406 is mounted at the top of the stack with very liitle room between the top of the unit and the underside of the desk.  Its temperature is 45°C.

A Google search for "What is the normal CPU temperature of a network device?" had the following response:

"The normal CPU temperature for a standard network device (like a router, switch, or firewall) typically ranges between 45°C and 75°C (113°F to 167°F). Because many network appliances use passive cooling (heatsinks without fans), running warm to the touch is a normal characteristic of their design."