Direct Vent Water Heater Venting Requirements

Vent adapter is needed to connect the water heater which is tankless to the exhaust hose.

Direct vent water heater venting requirements.

All emission of liquid or gas water heaters which are tankless needs vent pipes made of stainless steel and approved by ul. For this reason common venting configurations are no longer allowed in some code jurisdictions where direct venting or power venting of water heaters is now mandatory. The water heater must be properly vented to the outdoors. In addition to venting gas and propane water heaters need an air supply for combustion.

18 minimum from the ground and 12 from ceiling overhangs. Illustrations of proper gas fired water heater venting using type b double wall vent pipe through a roof above or through a chimney below include details for the flue vent connector such as the requirement of a minimum vent connector upwards slope of 1 4 per foot of horizontal run. Above the air intake inlet. In direct vent applications this clearance distance must be in compliance with local building codes the requirements of the fuel gas supplier for the heating appliance in use and the appliance manufacturer s instructions.

When determining the installation location for a direct vent water heater snow accumulation and drifting should be considered in areas where applicable. The natural gas fueled water heater shown at page top is improperly vented lacking the recommended minimum 12 of vertical rise before the elbow and vented directly into a large masonry flue where it cannot develop adequate draft. For non direct vent applications that is side wall venting only the required clearance is 7 feet. Never operate the water heater unless it is vented to the out doors and has adequate air supply to avoid risks of improper operation explosion or asphyxiation.

See figures 4 through 8 and items below. As you can read in our citation of direct vent and sidewall vent clearance distance requirements in the faqs below the outlet inlet of the vent and air intake terminations shall be a minimum of 12 inches above highest anticipated snow level. Atmospheric venting works on the principle of hot air rising. This heater installation may be unsafe.

The venting must be vertical or upward sloping so that the hot exhaust rises up through the venting to exit your home. This difference in operation means that you can install a direct vent system almost anywhere. 18 minimum in all directions from any obstruction that may interfere. This venting may either be dedicated to the water heater or can be shared with other atmospheric vent appliances such as a furnace.

The vent outlet must be installed a minimum of 12 in.