Thermostat displays 'Battery Low' or shows a low-battery icon

Safety: Turn off power to the HVAC system if you will be removing the thermostat from the wall plate.

• Remove thermostat: Gently pull the Honeywell Home thermostat straight off the wall plate.
• Replace batteries: Install fresh, high-quality alkaline batteries of the correct size (commonly AA). Do not use rechargeable batteries unless specified by Honeywell.
• Clean contacts: If corrosion is visible on the battery contacts, gently clean them with a cotton swab and a small amount of isopropyl alcohol. Allow them to dry fully.
• Reinstall thermostat: Snap the thermostat back onto the wall plate and confirm that the low-battery warning clears.
• Check C-wire: If batteries drain quickly, verify that the thermostat has a proper C-wire connection to provide continuous power and reduce battery usage.