From the manual’s warnings section:
Dixell controllers typically feature two programming levels to prevent accidental changes to critical system settings. dixell controllers manual
She went back to the manual. Silencing the Alarm. dixell controllers manual
Time between defrost cycles (e.g., 8 hours). MdF (Maximum Defrost Time): Length of defrost, unless dtEd t cap E (end temperature) is reached. dixell controllers manual
The Silent Pulse
The display will show the current Set Point, and the “°C” or “°F” LED will begin blinking.