
8
# ISU ISU Name ISU Options (factory default in bold)
365 Compressor Cycle
Rate (Stage 1) 1 - 6
Note: This ISU is only displayed when Cool /Compressor Stage is set to 1 stage. Cycle rate limits the
maximum number of times the system can cycle in a 1 hour period measured at a 50% load. For
example, when set to 3 CPH, at a 50% load, the most the system will cycle is 3 times per hour (10
minutes on, 10 minutes off). The system cycles less often when load conditions are less than or
greater than a 50% load.
370 Heating Cycle Rate
(Stage 1) 1 - 12
Note: This ISU is only displayed when Heat Stage is set to 1 stage. Cycle rate limits the maximum
number of times the system can cycle in a 1 hour period measured at a 50% load. For example,
when set to 3 CPH, at a 50% load, the most the system will cycle is 3 times per hour (10 minutes
on, 10 minutes off). The system cycles less often when load conditions are less than or greater than
a 50% load. The recommended (default) cycle rate settings are below for each heating equipment
type: Standard Efficiency Gas Forced Air = 5 CPH; High Efficiency Gas Forced Air = 3 CPH; Oil
Forced Air = 5 CPH; Electric Forced Air = 9 CPH; Fan Coil = 3 CPH; Hot Water Radiant Heat = 3 CPH;
Steam = 1 CPH.
375 Heating Cycle Rate
Auxiliary Heat
(TH4210U only)
1 - 12
387 Compressor
Protection 0 = Off
1 - 5minutes
Note: The thermostat has a built in compressor protection (minimum off timer) that prevents the
compressor from restarting too early after a shutdown. The minimum-off timer is activated after the
compressor turns off. If there is a call during the minimum-off timer, the thermostat shows “Wait” in
the display. This ISU is displayed if ISU 220 is set to at least 1 stage.
425 Adaptive Intelligent
Recovery 0 = No
1 = Yes
Note: Adaptive Intelligent Recovery (AIR) is a comfort setting. Heating or cooling equipment will
turn on earlier, ensuring the indoor temperature will match the setpoint at the scheduled time.
430 Minimum Cool
Setpoint 50 °F to 99 °F (50 °F)
10.0 °C to 37.0 °C (10.0 °C)
Note: The cool temperature cannot be set below this level.
431 Maximum Heat
Setpoint 40 °F to 90 °F (90 °F)
4.5 °C to 32.0 °C (32 °C)
Note: The heat temperature cannot be set above this level.
435 Keypad Lockout Setting on Original T4 Models:
0 = None
1 = Partial
2 = Full
Setting on Current T4 Models:
0 = Disabled
1 = Enabled
Note: Due to customer feedback, this feature was changed. On the original software, you can
lockout the thermostat from the ISU the same as you can from menu lockout. For later versions, this
setting allows the contractor to enable or disable the lockout feature. When disabled, there is no
lockout option under menu. Lockout code is 1234.
702 Number of Air Filters 0- 2
Note: This ISU refers to the number of air filters in the system.
Advanced setup options (ISU) (continued)