My water heater vent runs to the basement wall. Right underneath (maybe 6 inches) is an opening (I’m not sure if that runs to where the vent goes out or not). Attaching a picture. Is there any reason the opening is there and shouldn’t be covered, or should I go get something to cover that with? Since hot air rises probably not an issue, but I guess if wind gets in it could blow in?

Thanks for any insight. enter image description here

  • What make and model is your water heater? – ThreePhaseEel Dec 27 '18 at 1:19
  • Hello, and welcome to Home Improvement. What's on the other side of the wall? Can you see where the hole runs? – Daniel Griscom Dec 27 '18 at 1:25
  • If the pipe comes out easy, put a flash light into the bottom opening and see if you can see it shining up past the top opening. Or better yet, use a camera to see if you can see the top hole from inside the bottom one. This will help us get a better idea of whats going on. – HazardousGlitch Dec 27 '18 at 3:51

Maybe I am not looking at the photo correctly but some times make up air is required, this can be for combustion or fresh air to keep the home liveable, more info would be needed in my opinion , if you close off air flow that supports combustion of a furnace it can cause furnace failures and high carbonmonoxide levels in the home.


I would blank that second hole off and silicone it tight. A simple piece of sheet metal could be used. I would make it air tight.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.