The Honeywell RTH8500D is a versatile programmable thermostat popular for its advanced scheduling and energy-saving features. When it experiences glitches, fails to respond, or displays erroneous readings, a reset can restore proper function. This guide explains how to perform a reset, what to expect, and how to troubleshoot common issues. It covers both soft resets and full factory resets, so users can choose the appropriate method for their situation. Clear, step-by-step instructions help ensure a successful reset without compromising system settings.

Overview Of Reset Options For The RTH8500D

The RTH8500D supports several reset types, each serving a different purpose. A soft reset restarts the thermostat’s software without wiping saved schedules or preferences, making it ideal for minor freezes. A hard reset or factory reset restores the device to original factory settings, erasing custom schedules and configurations. Understanding when to use each reset type helps avoid unintended loss of data while addressing the root cause of the problem.

Key reset types include:

Soft Reset: Reboots the device to clear temporary glitches while preserving user settings.
Restart Reset: Similar to a soft reset, often accomplished by powering the unit off and on or using a menu option.
Factory Reset: Restores default factory settings, erasing all custom schedules and configurations.
Installation/Settings Reset: Reverts specific installation or wiring-related parameters without touching personal schedules.

Preparation Before Reset

Before performing any reset on the RTH8500D, gather essential information and take precautions. Have the thermostat’s current schedule, heating and cooling settings, and any recent changes noted. If the thermostat controls an HVAC system, ensure you understand your system’s configuration, such as heat pump or conventional gas/electric heating. For safety, switch off the thermostat’s power at the breaker before performing a hard reset that requires disconnection from power.

Safety tips and preparation steps include:

Identify System Type: Confirm whether the unit serves a heat pump, conventional furnace, or another configuration to prevent incorrect settings after reset.
Note Current Settings: Record temperature setpoints, week/weekend schedules, and any custom feature like Eco or Away modes.
Power Considerations: For a full reset, ensure power is safely disconnected to avoid electrical issues.
Backup: If possible, take photos of wiring or screen displays to aid reconfiguration after reset.

Step-By-Step Reset Process

Proceed with the reset method that matches your goal. The following steps cover soft/restarter resets and a full factory reset for the RTH8500D. Each paragraph below corresponds to a discrete action you can perform directly on the thermostat.

Soft Restart Or Restart Reset

Soft resets are quickest and least disruptive. To perform a restart reset on the RTH8500D, use one of these methods:

From the home screen, navigate to Settings or System, then select Restart or Reset, and confirm.
Power off the thermostat at the equipment breaker for about 30 seconds, then restore power; the unit should reboot.

After a soft restart, verify that the display responds, and check whether the HVAC system responds to temperature changes. Re-enter any schedules or preferences if the system shows minor glitches.

Factory Reset

A factory reset should be used only when persistent issues remain or when reconfiguring a newly installed unit. Note that this erases user-defined schedules and configurations. Steps typically include:

Access the main menu, then go to Settings or System, then find Factory Reset or Restore Defaults.
Confirm the action when prompted. The thermostat will restart and return to factory defaults.
Reconfigure essential settings: system type (heat pump, conventional), equipment connections, date/time, and preferred schedules.

After performing a factory reset, re-enter the appropriate wiring and system configuration details to ensure the thermostat communicates correctly with the HVAC equipment.

Installation/Settings Reset (If Available)

Some models offer a targeted reset option that reverts only certain installation parameters, such as wiring type or sensor calibrations, without touching user schedules. If this option exists on the RTH8500D, follow the on-screen prompts to reset installation settings and then re-check system operation.

Tip: If you are unsure about which reset to choose, start with a soft restart. If problems persist, proceed to a factory reset while preparing to reconfigure essential settings.

Common Issues After Reset And Troubleshooting

Resetting a thermostat can require reconfiguring settings or addressing minor post-reset hiccups. Common issues include lost schedules, non-responsive touch screen, improper temperature readings, and HVAC system miscommunication. The following troubleshooting steps help resolve frequent problems after a reset:

Non-Responsive Screen: Ensure power is stable and the device is not frozen. Perform a soft restart if necessary.
Incorrect Temperature Readings: Recalibrate sensors if the option exists, or re-enter the correct sensor parameters during setup.
HVAC Not Responding: Verify wiring and system type. Confirm that the thermostat is set to the correct operating mode (heat, cool, auto).
Schedule Not Restored: Re-create or import schedules from a prior backup. Some units require manual re-entry after a factory reset.

For persistent issues, consult the user manual or Honeywell support. In some cases, a firmware update may address post-reset glitches and improve overall reliability.

Advanced Settings After Reset

Post-reset configuration ensures optimal performance and energy efficiency. The RTH8500D supports several advanced settings that can be tailored to a home’s comfort needs and energy targets. Key areas include:

System Type And Equipment: Set whether the system is a heat pump with auxiliary heat, conventional forced air, or another configuration. Correct wiring and sensor configuration are essential for accurate operation.
Programming And Schedules: Rebuild weekly schedules, including weekday and weekend temperature setpoints, heightening energy savings while maintaining comfort.
Energy-Saving Features: Enable Eco or Active Energy Management options if available. These can automatically adjust temperature settings during peak price periods or absences.
Alerts And Diagnostics: Enable system alert notifications and diagnostics to monitor equipment performance and catch issues early.

Regularly reviewing and updating these settings after a reset helps maintain comfort and efficiency while reducing the risk of future reset-related confusion.