HVAC Journeyman Practice Exam

Wall-type room heaters shall not be attached to walls of combustible material unless what condition is met?

1. Approved by Authority Having Jurisdiction

2. Opening lined with non-combustible material

3. Listed for such installations

4. Approved by the fire marshal

The correct answer is: Listed for such installations

Wall-type room heaters must be designed and tested for safe installation on walls that may contain combustible materials. When these heaters are listed for installations on such surfaces, it indicates that they have undergone rigorous testing to ensure that they do not pose a fire hazard under normal operating conditions. This listing ensures compliance with safety standards and affirms that the product is suitable for use in environments where there might be combustibles close to the heater. The other conditions mentioned, while potentially relevant in certain contexts, do not specifically address the fundamental requirement of having the heater itself listed for use in the described manner. For example, approval by an authority having jurisdiction or the fire marshal may be necessary in some cases, but the core requirement is that the heater is specifically approved for installation on combustible walls through appropriate listing. Similarly, simply lining openings with non-combustible material does not necessarily ensure the heater's safe operation; its inherent design and certification are critical. Thus, the correct choice emphasizes the importance of ensuring the product’s compatibility with potentially combustible surfaces through recognized listings.