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

Safety first: Most balancing adjustments can be done without opening the furnace.

• Adjust registers: Partially close registers in overheated rooms and fully open registers in cold rooms.
• Check returns: Ensure each major room has an open return path (door undercuts or return grilles).
• Inspect zone dampers: For Bryant zoning systems, verify motorized dampers are moving when different zones call. Stuck dampers may need replacement.

Persistent imbalance may require a duct design review and professional balancing.