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

Safety: Turn off power before adjusting blower wiring.

• Step 1 – Check registers and dampers: Open all supply registers fully. Adjust manual dampers in branch ducts to balance airflow between rooms.
• Step 2 – Inspect returns: Ensure return grilles are not blocked and that doors undercut or transfer grilles allow air to return.
• Step 3 – Clean coil and filter: Replace the filter and have the Tempstar evaporator coil cleaned if dirty.
• Step 4 – Adjust blower speed: Consult the Tempstar installation manual to select an appropriate blower speed that balances comfort and airflow.