Why is 'Cool On' or 'Heat On' flashing on my thermostat screen?
The flashing 'Cool On' or 'Heat On' message means the compressor protection feature is engaged. This feature forces the compressor to wait a few minutes before restarting to prevent equipment damage. Wait 5 minutes for the system to restart safely. (Pages 46, 63)
From the official Honeywell RTH6580WF Wi-Fi Smart Thermostat manual, page 46
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