Honeywell PRESTIGE THX9321 - Manual (Page 27)

THX9321 PRESTIGE ® 2.0 AND THX9421 PRESTIGE ® IAQ WITH EIM
27 68-0311—02
2130 Backup Heat
Stages
0 - 2 1 Both No This ISU is only displayed when a backup
heat source is selected at ISU 2120 Backup
Heat Type.
Maximum of 2 Backup Heat stages.
2140 What Terminals are
Wired to Backup
Heat?
None
U1
U2 Default varies
based on
previous
selections
Both 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).
The thermostat can support up to 3
conventional heat stages. When there are a
total of 3 conventional heat stages, the last
stage of heat must be wired to 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.
2150 Backup Heat
Operation
NOT Allowed to Run with Primary
Heat
Allowed to Run with Primary Heat
NOT allowed to
run with
Primary Heat
Both No This ISU is only displayed when ISU 2010
Heating Equipment Type is Hot Water Fan
Coil, Electric Forced Air or Other.
When ISU 2010 Heating Equipment Type is
Hot Water Fan Coil, Electric Forced Air or
Other, you can select how the Backup Heat
operates. The thermostat can be setup to
keep the primary heat source on when it
calls for Backup Heat or the thermostat can
be setup to turn off the primary heat source
when it calls for Backup Heat.
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.
2160 Backup Heat Fan
Operation
No Fan
Equipment Controls Fan
Thermostat Controls Fan Thermostat
Controls Fan
Both No This ISU is only displayed for conventional
systems when ISU 2120 Backup Heat Type
is Electric Forced Air, Hot Water Fan Coil
or Other.
Backup Heat Fan Operation automatically
defaults to Equipment Controls Fan when
ISU 2120 Backup Heat Type is Standard
Efficiency Gas Forced Air, High Efficiency
Gas Forced Air or Oil Forced Air.
No Fan is only displayed when ISU 2120
Backup Heat Type is Other.
Table 4. Installer Setup (ISU) Table. (Continued)
ISU
Number
Installer Setup
Name Settings Default
Residential,
Commercial
or Both
Requires
EIM Notes