This class includes the installation of plumbing, heating and air-conditioning systems, including additions, alterations, maintenance and repair.

This class includes installation in buildings or other construction projects of :

heating systems (electric, gas and oil)

furnaces, cooling towers

non-electric solar energy collectors

plumbing and sanitary equipment

ventilation, refrigeration or air-conditioning equipment and ducts

gas fittings

steam piping

fire sprinkler systems

lawn sprinkler systems

Duct work installation

This class excludes installation of electric baseboard heating, see 4321.