Section 408.4294. Temperature combustion regulators.

(1) In addition to the mandatory requirements for a pressure relief device required by R 408.4278, an individual   automatically  fired hot water heating or hot water supply boiler in addition to the operating control used for normal boiler operation,  shall  have  a   separate high-limit-temperature-actuated combustion control that will cut off the fuel supply. The temperature range of a high-limit-actuated combustion control shall not allow a maximum setting over 250 degrees Fahrenheit and shall control the rate of combustion to prevent the temperature of the water from rising above 250 degrees Fahrenheit at  or  near  the  boiler outlet. Separate controls may have a common connection to the boiler.

(2) When it is known that the Btu input to a hot water supply boiler does not exceed 200,000 or the volume does not exceed  120  gallons,  the maximum setting of the high-limit control determines whether the hot water supply boiler is subject to these rules. The settings at which stops are inserted can be considered to be the determining factor if  the  setting   is with metallic fixed stops.

History: 1979 AC.