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Minimum On Timer
Once the equipment has been turned on, it must remain on for 3 minutes. A change
in mode or setpoint will cancel this timer.
Cycle Timer
Based on the selection of 2, 4, or 6 cycles per hour, this timer is set to 30, 15, or 10
minutes. This much time must elapse from the start of one cycle before another
cycle can start. It serves to impose the cycles per hour limits. It can be defeated for
one cycle by simultaneously pressing the FAN and UP keys.
Auto Changeover Timer
To prevent unnecessary cycling between heating and cooling modes, this timer
prevents a changeover to the opposite mode until a demand exists in the opposite
mode for 20 minutes. It is defeated when setpoints are changed so that the opposite
mode is immediately available if desired.
Error Codes
Two error messages indicate problems with the thermostat’s operation. If the room
temperature sensor fails, the temperature display will show ----, two dashes. If there
is an internal memory failure, the temperature display will show E4. The remedy for
each of these is to replace the thermostat.
Table 1 shows the thermostat outputs for each available stage of heating or cooling.
It may be useful in checkout or troubleshooting.
