How to Caulk Around a Boiler Vent Pipe

If your home utilizes hot water baseboards or underfloor heat, you most likely have a boiler. This boiler vents its combustion gases through a vent pipe that runs from the boiler to the chimney. Properly sealed vent pipes are essential to prevent them from leaking deadly carbon monoxide gases into your home. High temperature silicone caulk is the sealant of preference due to its ability to withstand the high temperatures that the vent pipe reaches.

Utility knife

Instructions

- 1
  Prepare high temperature silicone caulk tube. Slice through the tip of the caulk tube at a 45 degree angle with your utility knife. Pierce the seal inside the tip with the wire on the caulk gun.
- 2
  Load the caulk tube into the caulk gun. Press the trigger numerous times until the plunger is tight against the tube.
- 3
  Place the tip of the caulk tube up against a seam on the boiler vent pipe. Press the trigger to begin dispensing caulk on to the seam.
- 4
  Move the tip around the entire seam while dispensing caulk to lay down an even bead of high temperature silicone caulk.
- 5
  Caulk each additional seam in the same manner. Smooth the caulk with a wet finger to both neaten its appearance and to push it deep into the seam.

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