ANSI Z21.56A-2000/CSA 4.7A-M00

Scope

This standard applies to newly produced pool heaters for heating non-potable water stored at atmospheric pressure, such as water in swimming pools, spas, hot tubs and similar applications; for use with natural gas, manufactured gas, mixed gas, liquefied petroleum gases and LP gas-air mixtures. This standard also applies to pool heaters intended for installation at a distance less than 5 feet (1.52 m) from the inside surface of a pool or spa, also known as a close proximity heater. This standard also app lies to pool heaters for indoor installation with draft hoods which are factory equipped with automatic vent damper devices. This standard also applies to pool heaters of other than the direct vent type which are factory equipped with electrically operated or mechanically actuated automatic flue damper devices.