Special trade contractors primarily engaged in plumbing, heating, air-conditioning, and similar work. Sheet metal work performed by plumbing, heating, and air-conditioning contractors in conjunction with the installation of plumbing, heating, and air-conditioning equipment is included here, but roofing and sheet metal work contractors are classified in Industry 1761. Special trade contractors primarily engaged in electrical work are classified in Industry 1731.
- Air system balancing and testing-contractors
- Air-conditioning, with or without sheet metal work-contractors
- Boiler erection and installation-contractors
- Drainage system installation, cesspool and septic tank-contractors
- Dry well construction, cesspool-contractors
- Fuel oil burner installation and servicing-contractors
- Furnace repair-contractors
- Gas line hookup-contractors
- Heating equipment installation-contractors
- Heating, with or without sheet metal work-contractors
- Lawn sprinkler system installation-contractors
- Mechanical contractors
- Piping, plumbing-contractors
- Plumbing and heating-contractors
- Plumbing repair-contractors
- Plumbing, with or without sheet metal work-contractors
- Refrigeration and freezer work-contractors
- Sewer hookups and connections for buildings-contractors
- Sheet metal work combined with heating or
- Solar heating apparatus-contractors
- Sprinkler system installation-contractors
- Steam fitting-contractors
- Sump pump installation and servicing-contractors
- Ventilating work, with or without sheet metal work-contractors
- Water pump installation and servicing-contractors
- Water system balancing and testing-contractors