Register Boot Sealing: 2025 Energy Code Compliance Program

There are two scenarios where Raters are required to verify the register boots have been sealed to the surrounding material.

When register boot sealing is mandatory

1. New duct system – when the duct system being tested for duct leakage meets the CEC’s definition of a new duct system i.e. 75% or more of the duct system is new and the remaining 25% is accessible and can be sealed, the register boots MUST be sealed.
2. Sealing all accessible leaks, smoke and visual verification – For altered or existing duct systems that are unable to pass either the total duct leakage test at 10% or the leakage to outside test at 7%, and the system is being passed by the seal all accessible leaks, smoke and visual verification protocol, the register boots MUST be sealed.
   

Bottom Line
New duct system: register boots must be sealed!
Pass by smoke: register boots must be sealed!

How to seal register boots
Sealing on HVAC Installation