Oil-fired unit heaters must be tested in compliance with which standard?

The correct answer is based on the applicable standards for oil-fired unit heaters, which are primarily governed by safety and performance criteria set by testing organizations. UL 731 is the standard specifically addressing the safety requirements for oil-fired unit heaters. This standard provides guidelines that ensure the safe operation of these heaters under various conditions, including aspects like design, construction, and performance.

While UL 1995 pertains to air-conditioning and heat pump equipment, ANSI Z83.24 is related to gas-fired appliances, and ISO 9001 deals with quality management systems across various industries, they do not specifically address the testing and safety regulations for oil-fired unit heaters. Thus, UL 731 is the most appropriate standard for this equipment, ensuring compliance with safety protocols unique to oil-fired applications.