PDF Standards CSA 4.3-2017/ANSI Z21.10.3-2017
Gas Water Heaters – Volume III, Storage Water Heaters, With Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous, Includes Errata No. 1 (April 2019) and Errata No. 2 (August 2019)
standard by CSA Group, 09/01/2017