How to Install Fresh Intake Vents for a Gas Water Heater

Select a location for the fresh-air intake’s hood on the exterior wall of your house. The hood should not share a location with any vents, such as vents from your furnace, dryer or exhaust.

Trace the outside circumference of the pipe on the intake hood to outline its shape on your wall. Use a hole saw that matches the measurement of the pipe to cut out the hole. Insert the pipe into the wall, and screw the hood to the wall with wood screws or concrete screws. If any gaps remain, use caulk to seal the gaps.

Locate the return duct on your gas water heater. Depending on the water heater, it may be labeled, or you may need to refer to your owner’s manual.

Line the intake vent’s collar up with the return vent for the water heater. Place the collar close to the water heater, and trace the outline of the collar onto the vent.

Make an incision and trim out the hole with aviation snips, following the inside of the outline that you traced.

Push the collar into the hole, and fold the locking clips down into place to mount the collar to the duct.

Measure the distance from the collar to the hood pipe, and add 2 inches to that measurement. Measure the intake duct, and mark the previous measurement onto the duct where you need to trim.

Cut the duct to size with your aviation snips, and use a crimper to crimp the cut edges of the duct.

Slide the duct into place on both ends. Secure the connection sites with sheet metal screws and a drill. Place the screws a few inches apart all the way around the connection.

Apply a duct sealant to the connection sites according to the sealant's instructions.