Hot Water Heater Backdrafting

These heating devices are identified by the presence of a draft hood also called a draft diverter.

Hot water heater backdrafting.

The most common problem associated with water heater venting is a condition called backdrafting in which exhaust gases from the water heater fail to exit the home via the vent and instead end up in the house. Last week i blogged about how to determine if a water heater is backdrafting. For a water heater to draft properly it needs to have plenty of available air. If a water heater backdrafts it means that potentially hazardous exhaust gases are coming back into the home.

A water heater backdrafts when the exhaust gases from an atmospherically vented water heater spill out into the room rather than safely leaving the house through the vent. Backdrafting can have many causes but it is most commonly due to poor vent design or installation and or an imbalance of air volume in the home. A common source of backdrafting is orphaned water heaters. The main reasons for the backdrafting at the water heater are the poor vent installation and the obstructions found in the vent pipe.

Some water heaters will be right on the brink of backdrafting even with a proper installation and all it takes is a single bathroom exhaust fan to pull enough air out of the house to make the water heater backdraft. Backdrafting at a water heater is a common defect identified during home inspections and it s almost always a condition that the homeowner or occupant is not aware of. This happens when the exhaust gases from an atmospherically vented water heater spill out into the room rather than safely leaving the house through the vent. This problem affects mainly the atmospheric gas type water heaters that use the natural convection for the removal of the products of combustion known as the exhaust gases.

Another way dangerous backdrafting can occur is through improperly configured flues or flue blockages warns gromicko. Fuel fired water heaters boilers wall heaters and furnaces are designed to exhaust the by products of combustion to the outdoors through a flue. Exhaust gases contain carbon monoxide and high levels of moisture so this is always a condition that should be corrected.