Gas Hot Water Heater Venting

Back drafting is usually the result of an inadequate vent design.

Gas hot water heater venting.

Atmospheric venting refers to a system in which exhaust from the water heater naturally rises out of the appliance s combustion chamber then travels up through a standard chimney style flue. When installed correctly this venting arrangement works with an 80 gas furnace or lower than 80 gas water heater. One problem you need to avoid is back drafting. The process of burning of the gas is called combustion and it creates heat exhaust gases including highly poisonous carbon monoxide and moisture the water heater s ventilation system removes these byproducts from the home making it a critical safety feature.

Most tank type gas water heaters are atmospheric vent type and they are required to vent vertically and above the roof of a home. Two specialized types of water heaters direct vent and mechanical vent also called power vent are exempted from this code requirement. You see this most commonly with atmospheric configurations and it means that your exhaust isn t leaving the home. A water heater vent pipe can be used for this venting with a hot water heater vent cap for safety reasons.

Gas hot water heater venting problems. Make sure that the ventilation direct outside the house or else there is a chance of fire or explosion in the house. With a replacement high efficiency furnace the existing vent pipe does not work for water heater only because the vent is too large. The photo below shows typical combined furnace water heater venting.

All water heaters that burn natural gas or liquid propane lp gas require a venting system.