
VISIONPRO
®
8000 WITH REDLINK™
68-0312—03
24
215
Run Backup Heat
with Primary
No
Yes
No
Both
No
This ISU is only displayed when ISU 201
Heating Equipment is
Other.
When ISU 201 Heating Equipment is
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 201 Heating Equipment is
Radiant
Heat
, the thermostat keeps the Radiant Heat
on when it calls for Backup Heat.
216
Backup Heat Fan
Equip Controls Fan
Tstat Controls Fan
Tstat Controls
Fan
Both
No
This ISU is only displayed for conventional
systems when ISU 212 Backup Heat Type is
Electric
.
Backup Heat Fan Operation
automatically
defaults to
Equip Controls Fan
when ISU 212
Backup Heat Type
is
Gas/Oil.
217
Backup Heat
Stage 2
None
U1
Default varies
based on
previous
selections
Both
No
TH8321 Thermostat Only:
This ISU is only displayed on the TH8321
thermostat when it is wired directly to the
equipment (Equipment Interface Module is
NOT used).
The thermostat can support up to 2 backup
heat stages for heat pump applications. When
there are 2 backup heat stages, backup heat
stage 2 must be wired to U1.
U1 is a normally open dry contact when
configured for a stage of Heat. U1 requires
power from a system transformer or a
separate transformer.
218
Backup Heat Type
Electric
Gas/Oil
Electric
Both
No
This ISU is only displayed when ISU 201
Heating Equipment is
Air to Air Heat Pump,
Geothermal
or
Geothermal Radiant
and there
is at least one stage of backup heat.
See “Heat Pump and Backup Heat Operation”
219
External Fossil
Fuel Kit
No
Yes
No
Both
No
This ISU is only displayed when ISU 201
Heating Equipment is
Air to Air Heat Pump,
Geothermal
or
Geothermal Radiant
and ISU
218 Backup Heat Type is
Gas/Oil.
Table 2. Installer Setup (ISU) Table. (Continued)
ISU
Number
Installer Setup
Name
Settings
Default
Residential,
Commercial
or Both
Requires
EIM
Notes