16 Tex. Admin. Code § 9.304 - Unvented Appliances
An individual who services and repairs an LP-gas appliance not required by the manufacturer to be vented to the atmosphere is exempt from the requirement to obtain a Category D license as specified in § 9.6 of this title (relating to License Categories, Container Manufacturer Registration, and Fees). An individual who installs these unvented appliances to LP-gas systems by means of LP-gas appliance connectors is also exempt from Category D licensing.
Notes
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