try resetting the thermostat:
If your thermostat gives the "EE" error code, use the following instructions to reset the thermostat.
1.) Turn the ON/OFF switch to “OFF” position.
2.) Simultaneously depress and hold the MODE and ZONE push-buttons while turning the ON/OFF switch to “ON”. FF should appear in the LCD display until the MODE and ZONE push-buttons are released. If EE appears when the buttons released, do the reset again. If EE keeps coming back there is a communication problem with the cable.
3.) When a dip switch is turned on or off after initial configuration, a system reset will need to be done before the Comfort Control Center will recognize the updated selection. Any time a component is added or removed it would be best to do a reset. There are no repairs to be done to the Comfort Control thermostat.