11
Hydronic heating systems and radiant heating systems and related parts and accessories, namely propane, natural gas or oil fired boilers with expansion tanks, pumps, temperature sensors, piping and injection mixing controls; water heaters and parts and components thereof; propane, natural gas and oil boilers and related parts and accessories, namely expansion tanks, primary pumps, secondary pumps, temperature sensors, piping, and injection mixing controls; boilers to supply commercial or residential hot water; heating appliances, namely natural gas, propane and oil fired boilers connected to an under-slab or under floor distribution system or other radiant or space heating systems which may also supply hot water on demand; air delivery systems and air handling systems and parts and components thereof
37
Repairs and maintenance of heating systems, water heaters, and heating appliances and parts and components thereof
40
Manufacture and installation of heating systems, water heaters and heating appliances and parts and components thereof
42
Design of residential and commercial heating systems