Draft hoods that are pushed down or mispositioned, just like you see in this picture, is an issue I come across all the time. This water heaters draft hood is blocking the indoor air that is normally pulled out through the chimney as well as the poisonous exhaust gases from the water heater. This is an issue called backdrafting.
This issue is dangerous because exhaust gasses may build up in your home and kill you. This is a serious issue and need to be addressed by a licensed HVAC technician.
What should the draft hood look like?
In the photo above you see there is plenty of room for air to enter the vent and allow good drafting up the chimney. That means when the water heater is turned on, the exhaust gases can easily be pulled out the chimney.
