I got an old Cisco 2811 from ebay with cheap price. Out of box, I got below warning message.
*Sep 10 01:29:05.887: %ENVMON-4-FAN_LOW_RPM: Fan 1 service recommended
*Sep 10 01:29:05.887: %ENVMON-4-FAN_LOW_RPM: Fan 2 service recommended
*Sep 10 01:29:05.887: %ENVMON-4-FAN_LOW_RPM: Fan 3 service recommended
Yes, I got a defected one. I decided the box is on my lab and try below supress command to make the warning messges sleep forever.
Router(config)# logging discriminator FAN_WARNING msg-body drops Fan
Router(config)# logging message-counter syslog
Router(config)# logging buffered discriminator FAN_WARNING 6400
Router(config)# logging console discriminator FAN_WARNING
Router(config)# logging monitor discriminator FAN_WARNING
Yes, it just works.