The Ontario Building Code | Relief Valves
7.2.10.11. Relief Valves
(1) temperature relief, pressure relief, combined temperature and pressure relief and vacuum relief valves shall conform to ANSI Z21.22 / CSA 4.4-M, "Relief Valves for Hot water Supply Systems".
In Plain Language
Temperature relief, pressure relief, combined temperature-and-pressure relief, and vacuum relief valves must conform to the referenced ANSI/CSA standard for relief valves used on hot water supply systems.
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.