What to do if one room is hotter than the other?

When one specific room in your home is noticeably hotter than the rest of the house, you can follow a structured troubleshooting process to identify and correct the imbalance. First, inspect the supply and return vents in that warm room to ensure they are fully open, unblocked by furniture, and clean. Second, check your HVAC system's duct balancing dampers in the basement or crawlspace to make sure dampers leading to the warm room are fully open while others are adjusted. Third, evaluate solar heat gain by installing blackout curtains or reflective window films on west-facing windows that absorb intense afternoon sunlight. Fourth, check your attic insulation levels directly above that hot room. 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.