Honeywell THX9321 Prestige 2.0 Product Data page 26

®
THX9321 PRESTIGE 2.0 AND THX9421 PRESTIGE
ISU Installer Setup
Number Name
2090 What Terminals are
Wired to Cool -
Stage 4?
2100 What Terminals are
Wired to Heat -
Stage 3?
2110 Fan Operation in
Heat
2120 Backup Heat Type
68-0311—02
Table 4. Installer Setup (ISU) Table. (Continued)
Settings
None
U1
U2
U3
None
U1
U2
U3
No Fan
Equipment Controls Fan
Thermostat Controls Fan
None
Standard Efficiency Gas Forced Air
High Efficiency Gas Forced Air
Oil Forced Air
Electric Forced Air
Hot Water Fan Coil
Hot Water Radiant Heat
Other
®
IAQ WITH EIM
Residential,
Commercial
Default or Both
Default varies Commercial
based on
previous
selections
Default varies Both
based on
previous
selections
Thermostat Both
Controls Fan
None Both
26
Requires
EIM Notes
No Cool Stage 4 is only available if ISU 1010 is
Commercial.
Cool Stage 4 must be wired to a universal
terminal (U1, U2 or U3).
U1, U2 and U3 are normally open dry
contacts when configured for a stage of
Cool. U1, U2 and U3 require power from a
system transformer or a separate
transformer.
U3 is only available on the Equipment
Interface Module (EIM).
No THX9321 Thermostat Only:
This ISU is only displayed on the THX9321
thermostat when it is wired directly to the
equipment (Equipment Interface Module is
NOT used).
Heat Stage 3 must be wired to a universal
terminal (U1 or U2).
U1 and U2 are normally open dry contacts
when configured for a stage of Heat. U1
and U2 require power from a system
transformer or a separate transformer.
No This ISU is only displayed when ISU 2010
Heating Equipment Type is Electric Forced
Air, Hot Water Fan Coil or Other.
The thermostat automatically defaults to
Equipment Controls Fan when ISU 2010
Heating Equipment Type is Standard
Efficiency Gas Forced Air, High Efficiency
Gas Forced Air or Oil Forced Air.
No Fan is only displayed when ISU 2010
Heating Equipment Type is Other.
No This ISU is only displayed when ISU 2010
Heating Equipment Type is Hot Water
Radiant Heat, Steam, Hot Water Fan Coil,
Electric Forced Air or Other.
The list of Backup Heat Types will vary
based on the type of primary heat selected
at ISU 2010 Heating Equipment Type.
When ISU 2010 Heating Equipment Type is
Hot Water Radiant Heat, the thermostat
keeps the Hot Water Radiant Heat on when
it calls for Backup Heat.
When ISU 2010 Heating Equipment Type is
Steam, the thermostat keeps the Steam
Heat on when it calls for Backup Heat.
When ISU 2010 Heating Equipment Type is
Hot Water Fan Coil, Electric Forced Air or
Other, you can select how the backup
operates. See ISU 2150 Backup Heat
Operation.