Common issues that cause water heater backdraft include vent connector problems, vent or chimney blockage and insufficient combustion. Homeowners can address many of these issues without the need for professional assistance.
Homeowners should inspect the water heater for obvious damage and proof of backdraft. Improper drafting can lead to melted draft hoods, corrosion on or in the tank, heavy condensation on pipes and the release of moisture or fog from the area. Vent connectors can cause improper airflow, leading to backdraft. Solve many vent connector problems by ensuring that the connector pitches upwards at a slope that is at least 1/4 inch per foot. Sags and dips in the connector require straightening for proper operation.
Clearing away debris, dust, and insect or animal nests from vents and chimneys can help ensure proper airflow and prevent backdrafting. Installing a listed cap may prevent this sort of blockage from occurring in the future, and some states may require a cap as part of local code or ordinance compliance. Insufficient combustion issues may occur even after eliminating all other common backdraft reasons, preventing proper expulsion of potentially harmful gases. To safely deal with issues related to combustion, homeowners should consult a professional installer or HVAC contractor.