Water heaters deriving heat from fuels or
types of energy other than gas shall be constructed and installed in accordance with the approved standards referenced in Table
501.1(2), Section 505.3, or Section 505.4. Vents or chimneys
for such appliances shall be approved types. An adequate supply
of air for combustion and for adequate ventilation of heater
rooms or compartments shall be provided. Each such appliance
shall be installed in a location approved by the Authority Having
Jurisdiction and local and state fire-prevention agencies.
Storage-type water heaters and hot
water boilers deriving heat from fuels or types of energy other
than gas, shall be provided with, in addition to the primary
temperature controls, an overtemperature safety protection
device constructed, listed, and installed in accordance with
nationally recognized applicable standards for such devices
and a combination temperature and pressure-relief valve.
Oil-fired water heaters shall
be installed in accordance with NFPA 31.
Indirect-fired water
heaters shall comply with the applicable sections of the ASME
Boiler and Pressure Vessel Code, or to one of the other applicable standards shown in Table 501.1(2). Each water heater
shall bear a label in accordance with ASME requirements, or an
approved testing agency, certifying and attesting that such an
appliance has been tested, inspected and meets the requirements
of the applicable standards or code.
An indirect-fired water heater that incorporates a single-wall heat
exchanger shall be in accordance with the following
requirements:
- The heat transfer medium shall be either potable water or contain fluids recognized as safe by the Food and Drug Administration (FDA) as food grade.
- Bear a label with the word "Caution," followed by
the following statements:
- The heat-transfer medium shall be potable water or other nontoxic fluid recognized as safe by the FDA.
- The maximum operating pressure of the heat exchanger shall not exceed the maximum operating pressure of the potable water supply.
- The word "Caution" and the statements in letters shall have an uppercase height of not less than 0.120 of an inch (3.048 mm). The vertical spacing between lines of type shall be not less than 0.046 of an inch (1.168 mm). Lowercase letters shall be compatible with the uppercase letter size specification.