How to fix uneven room temperature?

Correcting stubborn room-to-room temperature imbalances in your house requires a systematic approach to airflow and distribution. First, check all supply registers and return grilles to ensure they are fully open and unblocked by furniture, rugs, or drapes. Second, adjust your HVAC system's duct balancing dampers in the basement or crawlspace to restrict excessive airflow to overly cold rooms while opening dampers wider for warm, distant spaces. Third, check and replace your indoor air filter to maintain strong blower performance. Fourth, evaluate solar heat gain by installing blackout curtains on west-facing windows or improving attic insulation. You can troubleshoot airflow velocity using your hand or an anemometer. You can verify that your corrective actions were successful when room-to-room temperature differences equalize within a comfortable two-to-four-degree range.