Controller Overtemperature (Internal)

What does OH4 mean?

The controller's internal temperature has exceeded its safe operating limit. This indicates that the controller is experiencing excessive load, has insufficient cooling, or its internal fan is failing. Sustained internal overtemperature will lead to derating, thermal shutdown, and reduced lifespan of internal components.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Inspect and test the internal cooling fan for proper operation; replace if defective.