Basic Mode; Precision Mode; Aux Mode; Turning Dehumidify On Or Off - Lennox CBX40UHV Series Installation And Service Procedure

to its dew point removing more moisture). At the same time,
the two‐stage outdoor unit will switch to high-speed to
produce a colder indoor coil. The colder indoor coil and
slower moving air combine to produce drier supply air.
NOTE - The indoor blower speed is reduced in order to slow
the air speed across the indoor coil. The supply air exiting
the unit may not feel as forceful. This is normal. Remember
that when the unit is in dehumidification mode, the comfort
level is increased because the unit is producing cooler, drier
air.
The exact sequence of operation to produce cooler, drier air
is described in the following section.
Other conditions adversely affecting
ComfortSense 7000 thermostat performance
Blower speed selection can adversely affect ComfortSense
7000 thermostat performance. Higher blower speeds
should be selected to provide maximum sensible cooling,
while lower blower speeds should be selected to provide
maximum humidity removal. Refer to the air handler and
thermostat installation instructions.
It is recommended that the indoor blower be left in AUTO
mode at all times. During dehumidification mode, the indoor
coil and drain pan may become saturated with moisture. If
the indoor blower is left in ON mode, much of that moisture
can be re-evaporated into the living space between
thermostat demands. This can create a constant demand
for humidity removal and may cause extended compressor
run times. Refer to table 8 for jumpers per application.
Table 8. Jumpers Required
Humidity Outdoor Unit
Control type
OFF Heat Pump
Condensing
Unit
ON Heat Pump
Condensing
Unit
Operation
Dehumidification is provided only when the thermostat is in
cool mode and may be set in the range of 45% to 60% RH.
Dehumidification D terminal wires to variable speed blower
(reverse logic/active on low signal 24VAC). When the unit is
CBX40UHV
Compressor Jumpers
type required
one-stage DS to Y1 &
Y1 to Y2
two-stage DS to Y1
one-stage DS to Y1 &
Y1 to Y2 &
O to R
two-stage DS to Y1 &
O to R
one-stage Y1 to Y2
two-stage None
one-stage Y1 to Y2 &
O to R
two-stage O to R
in heating mode, the dehumidification function is off. The
default mode for dehumidification is OFF and needs to be
activated during installation.
The D terminal is active whenever the ComfortSense
7000 thermostat is powered, EXCEPT when there is a
dehumidification demand. This means that the D terminal
has 24VAC on it even in HEAT and OFF modes.
Dehumidification only with a cooling demand. COOL is on,
then D is active (reverse logic off), and G comes on (if not
already on), Y1 and Y2 (if available) is on.
Dehumidification with or without a cooling demand. COOL
is on, the D is active (reverse logic, off), and G, Y1, and Y2
(if available) are on. Note that H is inactive (off) during
dehumidification. The D terminal controls dehumidification.
When a dehumidification demand is present, the D terminal
becomes de‐energized. Otherwise, 24VAC is present in off
mode and heating mode unless there is a call for
dehumidification.
Select this
Dehumidification Accessory is installed. Operation is same
as PRECISION mode but requires an outdoor sensor.
Select this mode when Whole Home Dehumidifier is used
in in a central or central/zoned installation. Operation is
same as PRECISION mode and can work with or without
AC on but G will be energized.

Turning DEHUMIDIFY ON or OFF

NOTE - One of the dehumidify modes must be turned on in
the INSTALLER SETTINGS before you can adjust the
dehumidify level in the USER SETTINGS of the
ComfortSense 7000 thermostat.
From the OPTIONS screen, scroll to INSTALLER
SETTINGS and press ENTER twice.
Scroll to HUMIDITY SETTINGS; press ENTER. Press the
box below DEHUMIDIFY.
HUMIDITY SETTINGS
HUMIDIFY DEHUMIDIFY
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Use up/down arrows to scroll to OFF, BASIC, PRECISION,
HUMIDITROL, or AUX; press ENTER.
DEHUM MODE SETTING
DEF(OFF) PRECISION
Default setting is 50% RH. Use up/down arrows to change
the %RH; press SAVE.
DEHUM SETPOINT
DEFAULT (5O%)
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BASIC mode

PRECISION mode

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HUMIDITROL mode
mode when Humiditrol

AUX mode

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45%
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Enhanced
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