Iowa Code Title III. Public Services and Regulation [Chs. 80-122C] § 89.4. Exemptions

a. Boilers of railway locomotives subject to federal inspection.

b. Boilers operated and regularly inspected by railway companies operating in interstate commerce.

c. Boilers under the jurisdiction and subject to inspection by the United States government.

d. Steam heating boilers and unfired steam pressure vessels associated with steam heating boilers and mobile power boilers used exclusively for agricultural purposes.

e. Heating boilers in residences.

f. Fire engine boilers brought into the state for temporary use in times of emergency.

g. Low pressure heating boilers used in buildings other than those for public assembly.

h. Hot water heating boilers used for heating pools or spas regulated by the department of inspections, appeals, and licensing pursuant to chapter 135I.

i. Water heaters used for potable water if the capacity is less than or equal to one hundred twenty gallons, the burner input is less than or equal to two hundred thousand British thermal units, and the maximum allowable working pressure is less than one hundred sixty pounds per square inch.

j. An electric boiler with a water capacity of six gallons or less that is used as an integral part of an espresso coffee machine, cappuccino coffee machine, or cleaning machine.

k. Continuous coil-type hot water boilers used only for steam vapor cleaning, to which all of the following apply:

a. A vessel not greater than five cubic feet in volume and not having a pressure greater than two hundred fifty pounds per square inch.

b. A vessel not greater than one and one-half cubic feet in volume with no limit on pressure.