Gas Water Heater Venting Options

With a replacement high efficiency furnace the existing vent pipe does not work for water heater only because the vent is too large.

Gas water heater venting options. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. Type l is stainless lined and used for oil and power gas heaters. The duct may be metal or plastic depending on the type of vent system. All venting installations must conform with local codes.

Atmospheric is the most common gas water heater venting option. All water heater venting systems use a vent duct or pipe also called a chimney or flue to bring exhaust gases from the water heater to the outdoors. Standard atmospheric water heaters are the most common type of residential gas water heaters. A concentric vent kit has both the intake and the outgoing in the same pipe.

Tankless water heaters use fans to blow exhaust from the unit horizontally allowing vents to terminate on the side of a house. The exhaust is in the center so that the outside of the vent does not heat up. Tankless water heaters can vent through the roof or a side wall creating more flexibility and options for placement. Type l vent is double walled vent.

The photo below shows typical combined furnace water heater venting. Power vented water heaters work the same as ordinary water heaters but the exhaust gases are blown out with a small fan instead of rising upwards through metal pipes. Water heater ducts may lead directly outdoors or they may tie into a larger vent duct that also serves a gas or propane furnace or boiler in the home. The hot exhaust gases from a natural draft water heater rise through an open draft diverter and out through a metal duct.

The venting system of the gas water heaters might consist of one or two pipes. There are two types of venting available for this type of tankless water heater. The difference is that a power vent water heater pulls in combustion air from the space around the appliance then uses a fan to propel the exhaust through the vent. A direct vent system pulls in.

The two pipe system. Traditional gas tank water heater require venting through the roof. There are concentric and dual. Type b due to its temperature rating can only be used with atmospheric gas water heaters.

Atmospheric gas water heaters vent their exhaust through a vertical or upward sloping metal duct vent to exit the home. The main problem with atmospheric vent systems is that they are susceptible to back drafts more on that later.