High Pressure Switch Kit includes required switch and instructions
for proper operation. For all dual fuel installations, outdoor
temperature sensor must be attached. If not, E3 error message will
appear. See "Error Codes."
This option requires prior selection of heat pump (DIP switch
1—ON), and must be selected in dual fuel installations. It prevents
simultaneous operation of both furnace and heat pump, and
prevents direct transition from heat pump to furnace operation.
When system is dual fuel (heat pump and furnace), set to ON.
When system contains fan coil, set to OF. Factory default is OF
(off).
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 10.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
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 11—DUAL FUEL CROSSOVER TEMPERATURE
This option requires prior selection of heat pump (DIP switch
1—ON) and dual fuel equipment (Option 10—ON). It allows
selection of an outdoor temperature of OF, 5, 10, 15, 20, 25, 30,
35, 40, 45, 50, or 55°F. Outdoor temperature sensor must be
attached. If temperature is selected and outdoor temperature sensor
is not attached, error message E3 will appear. Heat pump is
prevented from operating for outdoor temperatures below selected
temperature. If OF is selected, outdoor temperature does not affect
system operation. Factory default is OF (off).
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 11.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between OF, 5, 10, 15, 20,
25, 30, 35, 40, 45, 50, or 55 on large display. Factory
default is OF.
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 12—DEFROST HEAT SELECT
This option allows installer to select the amount of heat provided
by Thermidistat Control during a heat pump defrost cycle. This can
be very helpful in maintaining a comfortable leaving air tempera-
ture during defrost. The Thermidistat Control senses when defrost
is in progress by monitoring voltage placed on the O line by the
heat pump while defrosting. It responds by turning on selected
combination of W1 and W2 during defrost. Note that this is very
different from the operation of an ordinary thermostat, which
cannot sense defrost in progress and only turns on its W outputs in
response to a temperature demand. Combinations of W1 and W2
are selected via the following:
The selection procedure is given below. If 0 is selected, operation
is like that of an ordinary thermostat, and a wire is required
between W2 of outdoor unit and a selected W on indoor unit.
When selection 1, 2, or 3 is made, no wire should be connected
from outdoor W2 because this connection may override selection
made. Obviously the heater must be in 2 sections, and fan coil
jumper must be removed between W1 and W2 for there to be a
difference between selections 1, 2, and 3. For most heaters, W1 is
lower wattage heater, and W2 is higher, although some have equal
elements for W1 and W2. Consult fan coil/heater combination for
the actual wattage connected to each of W1 and W2.
In dual fuel applications, above selection choices apply and can be
used to select low or high heat if furnace is 2 stage. W1 will
produce low heat. W1 and W2 together produce high heat. This
option provides no value with single-stage furnaces because only
1 value of heat is available.
The selection choices guarantee selected outputs will be on during
defrost. If room temperature demand requires additional heat, it
will be supplied, resulting in additional outputs being turned on. If
room overheats, specified outputs will not turn off, guaranteeing a
sufficiently warm leaving air temperature during defrost. Tempera-
ture overshoot during defrost can occur, but is almost never
noticeable because of the short duration of the defrost cycle (4
minutes typical, 10 minutes maximum).
An additional feature of Thermidistat Control defrost is that it
always allows defrost cycle to run to completion. The Thermidistat
Control leaves the Y output on as long as outdoor unit holds
voltage on the O line, even if it is satisfied. This prevents
premature termination of defrost cycles, which occur with normal
thermostats.
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 12.
2. Press SET TIME/TEMP button once to flash large display.
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 home-
owners may want to have displayed temperature adjusted to a
higher or lower value. The selected number is number of degrees,
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° 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.
TABLE 1—W1 / W2 OUTPUTS
SELECTION
DEFINITION
0
Neither W1 or W2 is turned on.
This is factory default.
1
Only W1 is turned on.
2
Both W1 and W2 turned on.
3
Only W2 turned on (available
only if 3-stage heat is selected).
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