Jack Frost

What would cause frost to form of the outside of this plumbing vent?

simple answer, water vapor and cold temp


I’ve never seen frost on a plumbing vent, why this one?

There may be a blockage trapping Water vapors, In Canada they will even Freeze over
I use to to live in Canada if your wondering how someone in TN new that.

My guess is the pipe is generally colder than 32~ but the frost would only forms where there are water droplets. Can’t say why the moisture is there.

John Kogel

lol Barry :slight_smile:

Could be there is moisture in that specific area. Normally the air in a vent (depending on what it is venting) is just warm enough to prevent any freeze. I have seen this where the pipe is warmer that the air around, water vapor forms, temp drops, frost is formed.

me too, especially after others posted their reply

some of us are way too smart, present company, me, excluded :D:D:D