What standard must solid-fuel-fired water heaters comply with?

Solid-fuel-fired water heaters must comply with UL 2523, which is specifically tailored to address the safety and performance requirements for these types of appliances. This standard focuses on the construction, performance, and testing of water heaters that utilize solid fuels (like wood, coal, or biomass) to ensure they operate safely and efficiently.

UL 2523 encompasses guidelines that help prevent hazards associated with the use of solid fuels, including issues related to combustion efficiency, emissions, and overall appliance durability. Compliance with this standard is essential for manufacturers to demonstrate that their products are reliable and safe for consumer use.

The other standards listed, such as UL 1453, UL 174, and UL 300, pertain to different types of equipment. UL 1453 primarily covers the requirements for electric booster water heaters and other electrically powered appliances. UL 174 addresses the safety of water heaters (but not specifically for solid-fuel types), while UL 300 is related to fire protection systems and fire suppression equipment. Hence, the specific nature of UL 2523 makes it the correct answer for solid-fuel-fired water heaters, ensuring they meet the necessary safety and performance standards.