Step-by-Step

1. Open all registers; open dampers by loosening locknuts and turning the damper handles parallel to the duct.

2. Synchronize several thermometers by laying them together for 30 minutes and noting differences.

3. Place a thermometer in each room, 3 feet above the floor but not above a supply register.

4. Begin to partially damper rooms, beginning with the one where your home's thermostat is located.

5. Check the thermometers in each room for changes. Continue to adjust dampers until all rooms are approximately the same temperature.

Note: If you have central cooling, you may need to rebalance the system in summer. Mark the seasonal position of each damper to make these changes easy.