Thermostat shows 'Aux Heat' or 'Emergency Heat' running frequently, even in mild weather.

Safety first: No high-voltage work is required for thermostat settings.

• Step 1 – Verify system type: Ensure the thermostat is configured as a heat pump with auxiliary heat, not as straight electric heat.
• Step 2 – Adjust balance point: In advanced settings, adjust the outdoor temperature at which auxiliary heat is allowed to run, if available.
• Step 3 – Check outdoor sensor: Verify the outdoor temperature displayed by the thermostat is accurate; if not, troubleshoot the outdoor sensor.
• Step 4 – Monitor heat pump performance: If the heat pump cannot maintain temperature without aux heat in mild weather, have a technician check refrigerant charge and system capacity.