UL 834:2019 PDF Download

The UL 834:2019 standard outlines requirements for electric boilers used in commercial or industrial applications that utilize hot water or steam. These boilers may also be used for space heating in commercial, industrial, or residential settings.

The standard specifies that the boilers covered must be rated at 15,000 volts or less. They are to be installed in accordance with the National Electrical Code, NFPA 70, the International Mechanical Code, and the Uniform Mechanical Code. Each boiler consists of sheathed resistance-type heating elements and a vessel or tank constructed and inspected in accordance with the applicable sections of the ASME Boiler and Pressure Vessel Code.

Safety is a key focus of the standard, with each boiler required to be equipped with one or more safety valves or safety relief valves that conform to ASME requirements. The boilers must also have temperature and pressure regulating controls, including an integral limit control, as well as the necessary wiring and auxiliary equipment.

However, there are certain exclusions to the scope of these requirements. Appliances such as water supply boilers, commercial cooking or medical and dental equipment, and electrode-type boilers are not covered. Additionally, the standard defines three types of water heating boilers: high pressure, low-pressure hot-water and low-pressure steam, and miniature boilers, each with their own specifications and limitations.