ANSI Z21.20a-2000

Scope
 
 This standard applies to automatic gas ignition systems and components which perform the following functions:
1) ignite the gas at the main burner(s), or at the pilot burner(s) so it can ignite the main burner(s);
2) prove the presence of either the ignition source, the main burner flame, or both; and
3) automatically act to shut off the gas supply to the main burner(s), or to the pilot and the main burner(s), when the supervised flame or ignition source is not proved. This standard covers automatic gas ignition systems and components intended primarily for use with gas appliances having inputs of 400,000 Btu per hour (117 228 W) or less per individual combustion chamber. This standard applies to automatic gas ignition systems and components for use with one or more of the following gases, natural, manufactured, mixed, liquefied petroleum and LP gas-air mixtures. This standard also applies to automatic gas ignition systems which also serve as oxygen depletion safety shutoff (ODS) systems.