Thermostat shows E5 and system may shut down or run in limited mode; humidity control may be disabled.

Safety first: Turn off power to the HVAC system at the breaker before removing the thermostat.

Steps to troubleshoot:

• 1. Power cycle and reset: Remove the thermostat from its wall plate for 30 seconds, then reinstall. If available, perform a factory reset from the settings menu (note: this will erase custom settings).
• 2. Inspect thermostat environment: Ensure the thermostat is not installed in a very damp area (e.g., near a bathroom or kitchen steam source). Excess moisture can damage the humidity sensor.
• 3. Check for physical contamination: Lightly dust the thermostat exterior; do not spray cleaners directly on it. Liquids entering the housing can damage the sensor.
• 4. Compare humidity readings: Use a separate hygrometer near the thermostat to compare readings. If the thermostat is far off and E5 persists, the internal humidity sensor is likely defective.
• 5. Replacement: The humidity sensor is integrated and not serviceable separately. Replace the Bryant smart thermostat if humidity sensing is required for dehumidification or ventilation control.