Codes & Standards - Purchase
ANSI Z21.23-1993 (R1998)
This standard applies to newly produced gas appliance thermostats of the integral gas valve or electric type (see Part IV, Definitions), either individual or in combination with other controls, constructed entirely of new, unused parts and materials.
This standard does not apply to an electric type comfort heating thermostat (wall-mounted) for installation remote from an appliance.
When the operating performance characteristics of the thermostat can be affected by the separate components, such as power supply, transformer and valve(s), the thermostat shall be tested as part of a complete system.
Compliance of a device with this standard does not imply that such device is acceptable for use on gas appliances without supplemental tests with the device applied to the particular appliance design.
An accessory incorporated as an integral part of a thermostat shall comply with all provisions of the applicable standard for such a device.
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.
All references to psi throughout this standard are to be considered gage pressure unless otherwise specified.
Exhibit A contains a list of standards specifically referenced in this standard, and sources from which these reference standards may be obtained.