Honeywell THX9421 Thermostat User Manual


 
THX9321 PRESTIGE
®
2.0 AND THX9421 PRESTIGE
®
IAQ 2.0 WITH EIM
68-0311—01 100
Backup Control
This section explains when backup control is used. For
example, if batteries in the wireless indoor sensors are
depleted.
If the Thermostat is Part of the Temperature
Average
1. The thermostat controls the system using the remaining
sensors that are part of the temperature average.
2. If there are no remote indoor sensors remaining, the
thermostat controls the system using its internal sensor.
3. If the internal thermostat sensor is not available and a
Return Air Sensor is connected, the Backup Control in
the EIM is used. This backup control maintains 55 °F in
heat, 85 °F in cool and operates the fan continuously to
sense and control temperature.
If the Thermostat is NOT Part of the
Temperature Average
1. The thermostat controls the system using the remaining
sensors that are part of the temperature average.
2. If there are no remote indoor sensors remaining and a
Return Air Sensor is connected, the Backup Control in
the EIM is used. This backup control maintains 55 °F in
heat, 85 °F in cool and operates the fan continuously to
sense and control temperature.
Replacing System Components
Follow steps below to disconnect the thermostat, EIM, and
RedLINK accessories.
To replace an Equipment Interface Module
(EIM)
AT THE THERMOSTAT
1. Press MENU > INSTALLER OPTIONS, then enter date
code when prompted (printed on back of thermostat).
NOTE: Or press MENU > EQUIPMENT STATUS to find
the date code.
2. Scroll down to select WIRELESS DEVICE MANAGER.
3. Press REMOVE DEVICE, then select THIS THERMO-
STAT to remove.
AT THE PORTABLE COMFORT CONTROL
1. Press and hold the blank space (or arrow if present) in
the lower right hand corner of the screen until the display
changes.
2. Press REMOVE, then YES to disconnect from the old
Equipment Interface Module.
AT THE INDOOR SENSOR, ENTRY / EXIT REMOTE,
REDLINK INTERNET GATEWAY OR TRUESTEAM
WIRELESS ADAPTER
1. Press and hold the CONNECT button on the RedLINK
accessory until the status light glows amber (hold for
about 10 seconds). This will disconnect the device from
the old Equipment Interface Module or thermostat.
RE-CONNECT THERMOSTAT AND REDLINK
ACCESSORIES
1. Follow the steps in “Link thermostat to EIM or True-
ZONE® Wireless Adapter” on page 10.
2. Follow the steps in “Link Optional RedLINK™ Accesso-
ries” on page 11.
To replace a thermostat that is being used
with an Equipment Interface Module (EIM)
AT THE EQUIPMENT INTERFACE MODULE
1. Press and hold the CONNECT button on the EIM until
the status light glows amber (hold for about 10 seconds).
This will disconnect ALL devices from the Equipment
Interface Module.
AT THE PORTABLE COMFORT CONTROL
1. Press and hold the blank space (or arrow if present) in
the lower right hand corner of the screen until the display
changes.
2. Press REMOVE, then YES to disconnect from the old
thermostat.
AT THE ENTRY / EXIT REMOTE AND REDLINK INTERNET
GATEWAY
1. Press and hold the CONNECT button on the RedLINK
accessory until the status light glows amber (hold for
about 10 seconds). This will disconnect the device from
the old thermostat.
RE-CONNECT THERMOSTAT AND REDLINK
ACCESSORIES
1. Follow the steps in “Link thermostat to EIM or True-
ZONE® Wireless Adapter” on page 10.
2. Follow the steps in “Link Optional RedLINK™ Accesso-
ries” on page 11.
To replace a thermostat that is NOT being
used with an Equipment Interface Module
(EIM)
AT THE PORTABLE COMFORT CONTROL
1. Press and hold the blank space (or arrow if present) in
the lower right hand corner of the screen until the display
changes.
2. Press REMOVE, then YES to disconnect from the old
thermostat.
AT THE INDOOR SENSOR, ENTRY / EXIT REMOTE,
REDLINK INTERNET GATEWAY OR TRUESTEAM
WIRELESS ADAPTER.
1. Press and hold the CONNECT button on the RedLINK
accessory until the status light glows amber (hold for
about 10 seconds). This will disconnect the device from
the old thermostat.
RE-CONNECT REDLINK ACCESSORIES
1. Follow the steps in “Link Optional RedLINK™ Accesso-
ries” on page 11.