enter image description here

All pics show are the Vent Cap, which is the exhaust and the inlet air cap. What is used for a RAINCAP?

  • What pics are you referring to? If you intended to include some, please edit your question to try again - hit the "sun & mountain" button to include them, or just drag the pics into the text edit box. If you didn't intend to include pics, adding some of your installation, plus an example of what you're referring to would probably help a lot. Also, what device are you venting? Plumbing? HVAC? All?
    – FreeMan
    Nov 21, 2023 at 15:43
  • Also, please revise your title to ask a clear, specific question. Take the tour to learn how this site works.
    – isherwood
    Nov 21, 2023 at 15:47
  • Trying to figure out how to add pics so everyone can see what I am asking about. Anyone have ideas about that?
    – Donald
    Nov 21, 2023 at 16:02
  • 1
    Look at the post editor. Click the picture icon. It's fairly intuitive. The first comment lays it out for you.
    – isherwood
    Nov 21, 2023 at 16:56
  • Does it need a rain cap? If so, there should be plenty of options to pick from at your local big-box home improvement store.
    – FreeMan
    Nov 21, 2023 at 19:47

1 Answer 1


There is no rain cap with this type of vent termination. "Why not?" you may ask?

The exhaust piping from a condensing appliance is designed to carry liquid. The appliance category is named "condensing" because these appliances extract so much heat from the exhaust gas stream that the water vapor condenses to liquid on the walls of the exhaust (vent) pipe.

It's ok if some precipitation enters the vent pipe because the pipe is liquid tight and is designed to drain these liquids back to the appliance itself. The appliance has a drain hose and sometimes a pump to remove these liquids out to the building sanitary sewer system. Clearly this arrangement can't handle the volume of water that a plumbing vent could, but it is sufficient to handle ordinary condensate and weather volumes.

The vent cap of the concentric vent, or a down-turned elbow in a two-pipe arrangement, sheds precipitation so that the combustion air inlet remains dry.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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