Optional Remote Outdoor Sensor
The outdoor sensor (X2658) may be required, especially when using Humiditrol® EDA applications. In addition to measuring and displaying outdoor temperature, the outdoor sensor provides dew point adjust- ment and control for all models. If used with this thermostat, the sensor enables optimal heating equipment operation via programmable bal- ance points. The screen will display NO OUTDOOR SENSOR until the outdoor sensor is installed, the feature is turned on in the USER SET- TINGS, in the DISPLAY INFO option. The outdoor temperature is dis- played in the information display (lower center of the screen).
NOTE − For proper operation of Humiditrol® EDA applications, the outdoor sensor MUST be installed.
In many applications, the ComfortSense® Model L7742U thermostat displays the temperature sensed by the remote outdoor sensor. With the heat pump system, the remote outdoor sensor helps determine when to turn on the second stage of heating for optimal comfort.
When the outdoor sensor is connected, the temperature displays in the information display area (below the indoor temperature display).
Memory Protection
The thermostat stores all the information concerning its programming (state, mode, program information, last temperature measured) in a nonvolatile memory.
This function avoids the loss of the state of the thermostat when a pow- er−down occurs. The only thing that might be lost is the clock, however, a lithium battery will remember clock information for as long as it has charge (approximately 30 days). When power down occurs (due to a power outage) the thermostat is able to switch off all relays. The O and B relay will maintain their last state.
Service Reminders
The user may turn on and turn off the following service reminders (all of which default to OFF) in either chronological time and/or run time and may be reset (to default) or delayed (snooze) at any time:
Replace Media Filter
Routine Sys (System) Check−up
Replace Hum (Humidifier) Pad
Replace UV Lamp
PureAirt Maintenance
NOTE − When chronological time is selected, the timer runs based on the calendar. When time is selected in run time, the timer runs based on the time the specific output is ON (e.g. Fan output for Media Filter).
When the reminder time (either calendar time or run time) has elapsed, the system displays a screen from which the user can either RESET or DELAY the reminder.
The user can reset the timer either before it has expired (i.e. reminder is set to 6 months and user decides to reset it to 6 months or change it to different value at the end of 4th month) or when the time has expired and a reminder message has been displayed.
When a reminder is turned off, the indicator will not be activated even if the timer is expired. Note that setting filter reminder to 0 (OFF) will not reset the timers, but will deactivate the filter indicator.
In the case of a power interruption:
Slithium battery has charge
tained (i.e. the counter does not recycle to zero).
Slithium battery has NO charge tained.
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