10/23/2026
🔧 Honeywell Home ProSeries Thermostat – Complete Advanced Settings (ISU) Guide
Prime Genius Heating & Air | Sacramento, CA
Are you trying to configure your Honeywell ProSeries thermostat for a heat pump or conventional HVAC system? Here’s a helpful guide to understanding the Installer Setup (ISU) menu.
HOW TO ACCESS ADVANCED SETTINGS
1. Return to the thermostat home screen.
2. Press and hold the Menu and + buttons together for approximately 5 seconds on supported models.
3. Enter Installer Setup (ISU).
4. Use the + and − buttons to navigate the settings.
5. Review the equipment configuration before making changes.
HVAC SYSTEM CONFIGURATION
◈ ISU 200 – System Type: 1 = Conventional, 2 = Heat Pump, 3 = Radiant, 5 = Cooling Only
◈ ISU 205 – Heating Equipment Type: 7 = Air-Source Heat Pump
◈ ISU 218 – Reversing Valve: 0 = O (Cooling), 1 = B (Heating)
◈ ISU 220 – Compressor/Cooling Stages: 1 = Single Stage
◈ ISU 221 – Heating/Backup Stages: Depends on system configuration
◈ ISU 230 – Fan Control: Equipment or thermostat controlled
HEATING & COOLING OPERATION
◈ ISU 300 – Heat/Cool Changeover: 0 = Manual, 1 = Automatic
◈ ISU 365 – Compressor Cycle Rate: 3 cycles per hour
◈ ISU 370 – Heating Cycle Rate: 3 cycles per hour
◈ ISU 387 – Compressor Protection: 5-minute delay
COMFORT & TEMPERATURE SETTINGS
◈ ISU 120 – Programmable Schedule: 3 = 5-1-1 schedule
◈ ISU 425 – Adaptive Intelligent Recovery: 1 = Enabled
◈ ISU 430 – Minimum Cooling Setpoint: 50°F
◈ ISU 435 – Keypad Lockout: 0 = Unlocked
MAINTENANCE & CLOCK SETTINGS
◈ ISU 702 – Air Filter Reminder: 0 = Disabled
◈ ISU 1410 – Clock Format: 12-hour
◈ ISU 1415 – Clock-related setting (model dependent)
◈ ISU 1420 – Daylight Saving Time: 0 = Disabled
IMPORTANT HVAC TECHNICIAN NOTE
Incorrect thermostat programming can cause heating and cooling problems, particularly with heat pump reversing valves, auxiliary heating, compressor staging, and fan operation.
Installer settings vary by thermostat model. Always verify the equipment model, thermostat wiring, and manufacturer’s installation instructions before changing system configuration.
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Prime Genius Heating & Air
📍 Sacramento, California
📞 (916) 800-4007
🌐 www.PrimeGeniusInc.com
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