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

Safety: Turn off power before opening duct access panels.

• Check registers: Ensure all supply and return registers are open and unobstructed.
• Adjust dampers: If your ducts have manual dampers, partially close those serving overheated rooms and fully open those serving cold rooms.
• Inspect accessible ducts: Look for crushed or disconnected flexible ducts in accessible areas like basements or attics.
• Filter: Replace a dirty filter to restore airflow.

For persistent imbalance, a professional may need to adjust blower speed settings on the Alpha control board or redesign ductwork.