Furnace runs but some rooms are too cold while others are too warm.

Safety: Turn off power before removing panels or filters.

Steps:

• Check filter: Replace a dirty filter to restore airflow.
• Adjust registers: Partially close registers in overheated rooms and fully open registers in cold rooms to balance airflow.
• Inspect ducts: Look for crushed, disconnected, or poorly insulated ducts, especially in unconditioned spaces.
• Blower speed: A technician can adjust blower speed taps or ECM settings on the Atlantic control board to optimize airflow.

Note: Severe imbalance may require duct modifications.