Honeywell T6 Pro Installation Instructions Manual page 9

Advanced setup options (ISU)
# ISU ISU Name
221 Heat Stages / Backup Heat Stages
230 Fan Control in Heat
253 Aux/E terminal control (Fixed to
"0" setting on all models except
TH6320U)
255 Backup Heat Source
(Heat Pump Only)
(TH6320U / TH6220U only)
256 Emergency Heat Source (TH6320U
only)
260 External Fossil Fuel Kit
(TH6320U / TH6220U only)
300 System Changeover
303 Auto Changeover Differential
340 Backup Heat Droop
350 Upstage Timer for Backup Heat
355 Compressor Lockout / Balance Point
356 Outdoor Lockout Backup Heat
365 Compressor Cycle Rate (Stage 1)
366 Compressor Cycle Rate (Stage 1)
370 Heating Cycle Rate (Stage 1)
371 Heating Cycle Rate (Stage 2)
375 Heating Cycle Rate Auxiliary Heat
378 Heating Cycle Rate Emergency Heat
(TH6320U only)
ISU Options (factory default in bold)
Heat Stages: 1, 2
Backup Heat Stages: 0, 1
1 = Equipment Controls Fan
2 = Thermostat Controls Fan
0 = Drive both Aux & E together
1 = Aux and E independent
1 = Electric Forced Air
2 = Gas/Oil Forced Air (or Fossil Forced Air)
1 = Electric Forced Air
2 = Gas/Oil Forced Air (or Fossil Forced Air)
0 = Thermostat Controls Backup Heat
1 = External Fossil Fuel Kit Controls Backup Heat
0 = Manual
1 = Automatic
0 °F to 5 °F
0.0 °C to 2.5 °C
Note: Differential is NOT deadband. Honeywell uses an advanced algorithm that
fixes deadband at 0 °F. The differential setting is the minimum number of degrees
from set-point needed to switch from the last mode running (heat or cool) to the
opposite mode when the thermostat is in auto-changeover. This is more advanced
than previous thermostats.
0 = Comfort
2 = 2 °F
3 = 3 °F
4 = 4 °F
5 = 5 °F
6 = 6 °F
7 = 7 °F
8 = 8 °F
Note: 0 (comfort) setting only available if backup heat (ISU 255) is set to electric.
0 = Off
1 = 30 minutes
2 = 45 minutes
3 = 60 minutes
4 = 75 minutes
5 = 90 minutes
6 = 2 hours
7 = 3 hours
-- = Off
5 °F to 60 °F (in 5 °F increments)
-15.0 °C to 15.5 °C (in 2.5 °C or 3.0 °C increments)
Note: Use a wired sensor to set compressor lockout / balance point on TH6320U
/ TH6220U.
-- = Off
5 °F to 65 °F (in 5 °F increments)
-15.0 °C to 18.5 °C (in 2.5 °C or 3.0 °C increments)
1 - 6
1 - 6
1 - 12
1 - 12
1 - 12
1 - 12
9
9 = 9 °F
10 = 10 °F
11 = 11 °F
12 = 12 °F
13 = 13 °F
14 = 14 °F
15 = 15 °F
8 = 4 hours
9 = 5 hours
10 = 6 hours
11 = 8 hours
12 = 10 hours
13 = 12 hours
14 = 14 hours
16 = 16 hours