N.H. Rev. Stat. Ann. § 362:4-d

The term "public utility" shall not include any corporation, company, association, joint stock association, partnership, or person, their lessee, trustee, or receiver appointed by any court, or assignee, by virtue of its being engaged in the manufacture, furnishing, or sale of hot water through a district energy system. In this section, "hot water" means water that has a temperature of no more than 200 degrees Fahrenheit that circulates in a district heating system under pressure of no more than 232 pounds per square inch.