Two gas appliances on one flue

Heating · Masonry Chimneys · printed page 170 (PDF page 171)

Book index entries

Gas Appliance – Two on One Flue One Flue – Serving Two Gas Appliances Single Flue Serving Two Appliances Two Gas Appliances on One Flue

Text in the illustration

chimney
gas furnace
two gas appliances on the same level are often vented through one flue (e.g. basement water heater and furnace)
in many areas venting through a single flue is permitted even if the appliances are on different levels
cross section

Generated explanation

A house cross section shows two gas furnaces on different levels connected to a single chimney flue. Each furnace has a separate vent connector entering the vertical flue at its respective level. The chimney extends above the roof along the side of the house. The annotations explain that two gas appliances on the same level often share a flue and that, in many areas, appliances on different levels may also share one. No specific defect is indicated.

Components

chimney shared chimney flue gas furnaces vent connectors floor assembly roof

Materials

masonry metal vent piping