What is the EE message on the DuoTherm Comfort Control Center?

It means that an error has occurred. If you have a 4 button comfort control. Follow these steps to reset:
To initiate a RESET, do the following in the order
listed:
1) Turn control on to ensure annunciator data and light are present. If data and light are present, continue to next step. Depress MODE switch to activate annunciator light.
Simultaneously depress the bottom two buttons (temperature UP and DOWN) and hold.
While holding these buttons down, depress the MODE button once and release.
Release the two buttons previously held down. Depress the MODE button once again.
At this time the light should extinguish, and the mode should register “OFF”. If not, repeat these steps.
Retest system ensuring that all functions are present
and operational.

If you have the five button comfort control. Turn the unit off and hold down the mode and zone buttons together. While holding them down, turn the thermostat back on. Hold the buttons down until an FF appears on the screen. Release the buttons and the display should return to normal. If not, try it again.