6
3. Use up or down buttons to move between 0, 1, 2, or 3 (if
available) on large display. See Table 1 for effect of these
choices. Factory default is 0.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to
exit configuration mode.
Option 13—Room Temperature Offset Adjust
This option allows calibration (or deliberate miscalibration) of
room temperature sensor. There are various reasons why
homeowners may want to have displayed temperature adjusted to
a higher or lower value. The selected number is number of
degrees Fahrenheit, plus or minus, which will be added to actual
temperature. The numbers can range between --5 and +5. Factory
default is 0. This adjusted value will be used as actual temperature
for both display and control action. For example, if 2 is selected,
72
_
F actual will read 74
_
F. If set point is 72
_
F, the room will
control to an actual temperature of 70
_
F which will be displayed
and acted upon as if it were 72
_
F. The effect is that a positive
number selection will make the room temperature lower and vice
versa. The Thermidistat Control is calibrated within an accuracy
of plus or minus 1
_
F when shipped from the factory, so this
adjustment will provide the best accuracy when set to 0.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
“To Enter Configuration Mode.” Use up and down
buttons to make small (now flashing) display indicate 13.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between --5, --4, --3, --2,
--1, 0, 1, 2, 3, 4, or 5 on large display. Factory default is 0.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to
exit configuration mode.
Option 14—Heat/Cool Dead Band Adjustment
This option selects the minimum difference between heat and
cool set points. A larger difference saves energy and a smaller
difference decreases temperature difference between heating and
cooling. Factory default is 2, which means cooling set point must
be a minimum of 2
_
above heating set point. An attempt to move
them closer will result in one “pushing” the other to maintain the
required difference.
Depending on set points, moving dead band closer than 2
_
may
result in regular cycling between heat and cool when AUTO
mode is selected. However, this cycling cannot occur more often
than 1 transition every 20 minutes. The system has a built--in
requirement that it cannot switch between heat and cool without a
20 minute “off” time between the 2 operations. Specifically, to
switch from 1 mode to the other, there must be no demand for the
old mode and a demand for the new mode, and this must exist
continually for 20 minutes before transition to the new mode will
occur.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
“To enter Configuration Mode.” Use up and down buttons
to make small (now flashing) display indicate 14.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between 0, 1, 2, 3, 4, 5,
or 6 on large display. Factory default is 2.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to
exit configuration mode.
Option 15—Enable Auto Mode
This option allows the installer to enable or disable AUTO mode
(automatic changeover between heat and cool). When disabled,
AUTO icon does not appear when successive presses of MODE
button are used to move between OFF, HEAT, COOL, and
EHEAT (in heat pump systems). Factory default is ON (AUTO
enabled).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
“To Enter Configuration Mode.” Use up and down
buttons to make small (now flashing) display indicate 15.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up and down buttons to move between OF and ON
on large display. Factory default is ON (AUTO enabled).
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to
exit configuration mode.
Option 16—Enable Super Comfort Heat Mode
This option requires prior ON selection of heat pump (DIP switch
No. 1) and Configuration Option No. 5 (Select Variable--Speed
Blower). Super Comfort Heat mode is part of the Comfort Heat
Pump system, which comprises a selected combination of
Thermidistat Control, variable stage Fan Coil, and 3--stage
electric heater to provide superior heat pump leaving air
temperatures under all conditions. This option selection modifies
heat pump blower and auxiliary heat operation to contribute to
comfortable leaving air temperature. Specifically, this selection
provides:
S
Reduced heat pump airflow for outdoor temperatures between
12
_
and 40
_
F.
S
At least 1 stage of electric heat ON for all heating below 12
_
F.
While outdoor air temperature is between 12
_
F and 40
_
F, the
Thermidistat Control removes the G signal during heat pump
heating. The 40FK, FK4C, or FV4A Variable--Speed Fan Coils
respond by reducing their airflow in the absence of the G signal,
raising leaving air temperature. For any heating demand below
12
_
F, G and W/W1 are turned ON, assuring at least 1 stage of
electric heat is on, and also increasing leaving air temperature.
A99059
Fig. 2
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Programmable/Non--Programmable Keypad Labels
TST
AT
