1.1 Scope 1.1.1 This standard applies to newly produced, large automatic storage water
heaters having input ratings above 75,000 Btu per hour (21 980 W),
instantaneous water heaters, circulating water heaters, including booster water
heaters (see Part IV, Definitions), hereinafter referred to as water heaters or
appliances, constructed entirely of new, unused parts and materials: a. For use with natural gas; b. For use with manufactured gas; c. For use with mixed gas; d. For use with liquefied petroleum gases; and e. For use with LP gas-air mixtures. f. For recreational vehicle installation for use with liquefied petroleum
gases only (see 1.2.26); g. For manufactured home (mobile home) installation convertible for use with
natural gas and liquefied petroleum gases when provision is made for the simple
conversion from one gas to the other (see 1.2.25); and h. For recreational vehicle installation convertible for use with natural gas
and liquefied petroleum gases when provision is made for the simple conversion
from one gas to the other (see 1.2.26). These requirements also apply to automatic storage type water heaters for use
with combination potable water/space heating applications. Automatic storage water heaters having input ratings of 75,000 Btu per hour (21
980 W) or less are covered in Volume I. 1.1.2 Direct vent water heaters anticipated by this standard are essentially
balanced flue appliances with the air intake and vent outlet in close
proximity. Other designs shall be subjected to such additional tests as
believed necessary at the discretion of the testing agency. 1.1.3 Water heaters for installation in recreational vehicles shall be of the
direct vent type. 1.1.4 This standard also applies to water heaters with draft hoods which are
factory equipped with automatic vent damper devices (see Part IV, Definitions),
hereinafter referred to as vent damper devices. 1.1.5 This standard also applies to water heaters of other than the direct vent
type which are factory equipped with electrically operated or mechanically
actuated automatic flue damper devices (see Part IV, Definitions), hereinafter
referred to as flue damper devices. 1.1.6 If a value for measurement as given in this standard is followed by an
equivalent value in other units, the first stated value is to be regarded as
the specification, except as noted in 1.30.1 and 1.31.1. 1.1.7 All references to psi throughout this standard are to be considered
gauge pressures unless otherwise specified. 1.1.8 Exhibit D contains provisions that are unique to the United States. 1.1.9 Exhibit E contains provisions that are unique to Canada, 1.1.10 Special construction provisions applicable to a water heater designed
for use with an optional listed conversion kit are outlined under Exhibit f
(Optional Provisions of Listed Appliance Conversion Kits). 1.1.11 Exhibit G contains a list of standards specifically referenced in this
standard, and sources from which these reference standards may be obtained.
CSA 4.3-2001 history
2019CSA/ANSI Z21.10.3:19 • CSA 4.3-2019 Gas-fired water heaters, volume III, storage water heaters with input ratings above 75,000 Btu per hour, circulating and instantaneous
2015CSA ANSI Z21.10.3-2015/CSA 4.3-2015 Gas Water Heaters - Volume III, Storage Water Heaters, With Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous
2014CSA ANSI Z21.10.3-2014/CSA 4.3-2014 Gas Water Heaters - Volume III, Storage Water Heaters, With Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous
2013CSA ANSI Z21.10.3-2013/CSA 4.3-2013 Gas Water Heaters - Volume III, Storage Water Heaters, With Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous
2004CSA 4.3-2004 Gas Water Heaters Volume III, Storage Water Heaters, with Input Ratings Above 75,000 Btu per Hour, Circulating and Instantaneous Third Edition; CSA/ANSI Z21.10.3-2004
2002CSA 4.3-2001 Gas Water Heaters - Volume III, Storage Water Heaters, With Input Ratings Above 75,000 Btu Per Hour, Circulating and Instantaneous