This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance of an automatic gas ignition system and components. It is the result of years of experience in the manufacture, testing, installation, maintenance, inspection and research on automatic gas ignition system and components designed for utilization of gas. There are risks of injury to persons inherent in appliances that, if completely eliminated, would defeat the utility of the appliance. The provisions in this standard are intended to help reduce such risks while retaining the normal operation of the appliance.
Nothing in this standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of automatic gas ignition systems and components, the safety construction and performance of which may exceed the various provisions specified herein. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, revisions may become necessary. When they are believed desirable, recommendations or suggestions should be forwarded to the Chairman of Accredited Standards Committee Z21/83, 8501 East Pleasant Valley Road, Cleveland, Ohio 44131.
Safe and satisfactory operation of an automatic gas ignition system and components depends to a great extent upon its proper installation, use and maintenance. It should be installed, as applicable, in accordance with the National Fuel Gas Code, ANSI Z223.1, manufacturers' installation instruction and local municipal codes.
Users of this American National Standard are advised that the devices, products and activities within its scope may be subject to regulation at the Federal, state or local level. Users are strongly urged to investigate this possibility through appropriate channels. In the event of a conflict with this standard, the Federal, state or local regulation should be followed.
This standard applies to newly produced automatic gas ignition systems (see Part IV, Definitions) and components constructed entirely of new, unused parts and materials.
An automatic gas ignition system shall perform the following functions:
a. Ignite the gas at the main burner(s), or at the pilot burner(s) so it can ignite the main burner(s);
b. Prove the presence of either the ignition source, the main burner flame, or both; and
c. 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.
Components submitted for examination under this standard shall perform one or more of the above functions.
This standard applies to automatic gas ignition systems which also serve as oxygen depletion safety shutoff (ODS) systems (see Part IV, Definitions).
This standard covers automatic gas ignition systems and components intended primarily for use with gas appliances having inputs of 400,000 Btu/hr (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:
d. Liquefied petroleum; and
e. LP gas-air mixtures.
Compliance of an automatic gas ignition system or component with this standard does not imply that such a system or component of such a system is acceptable for use on gas appliances without supplemental tests with the device(s) applied to the particular appliance design.
Addenda 1 to ANSI Z21.20-2005, Automatic Gas Ignition Systems and Components