1711  Plumbing, Heating, and Air-conditioning

Establishments classified in this industry are primarily engaged in
plumbing, heating, or air-conditioning work or any combination of
these types of 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, Roofing, Siding, and Sheet Metal
Work Special Trade Contractors.