The Ontario Building Code | Expansion, Contraction and System Pressure
6.2.1.9. Expansion, Contraction and System pressure
(1) Heating and cooling systems shall be designed to allow for expansion and contraction of the heat transfer fluid and to maintain the system pressure within the rated working pressure limits of all components of the system.
In Plain Language
Heating and cooling systems must be designed to accommodate thermal expansion, contraction, and system pressure changes, preventing pipe or component failure from the normal thermal cycling these systems undergo.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.