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

Steps to check:

• Register adjustment: Open registers in cold rooms fully and slightly close registers in overheated rooms to balance airflow.
• Inspect accessible ducts: In basements or attics, look for disconnected or crushed ducts and repair with mastic or UL-181 foil tape.
• Filter and coil: Ensure the filter and evaporator coil are clean to maximize airflow.

For persistent imbalance, a technician can perform a duct analysis and adjust blower speed taps on the Coleman furnace to better match the duct system.