Air Admittance Valves - Have You Seen Them Fail Alot?

kyle181

Im curious if you've seen many problems with air admittance valves? i always hear from the old timers that they always fail eventually, just curious what your experience has been with them?

KillerToiletSpider

They aren't allowed by code here, but they get used occasionally, I have seen three of them that had the diaphragm rot and allow sewer gas in, I would expect this to be a common problem.

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A flush is better than a full house.

Ron The Plumber

A link to where studor vents are allowed by code.

http://www.studor.com/approvals.htm

Herk

I can't remember if I've seen one that failed, but then, our sewer gas isn't terrible here. I have one in an upstairs bath that has been in for quite a few years and I know it works because I can hear it. (Makes a sort of humming sound when I shut off the tap as air passes into it.)

I know that they can fail. But I also know that all the new manufactured homes in this area have them, and I don't get complaints.

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mdshunk

I get crawling around in attics every once in a while that have big one's in the attic. I can't speak to the frequency of failure, but I can say that they sometimes fail judging by the smell. Mind you, these are one's that are probably 20 years old or thereabouts. The occupants probably don't even notice the smell, since the attic itself is generally reasonably well ventilated.

gitnerdun

A failed one could allow bugs as well as odors to enter your home.

BigMikeB

Maybe that's because the vents last longer than the homes.

Pete M

Admittance valves can be problematic - whether they're old or new. They were originally designed for remodeling projects to minimize building damage created by plumbers chasing vent systems to tie in a new fixture.

I've smoke-tested lots of homes looking for those "mystery smells" no one could find. I have found quite a few failed Studor vents when they are installed below flood rim, under a lavatory or kitchen sink. Once a drain backs up and the admittance valve gets wet with soapy or greasy wastewater, you can bet it will fail. They "stick".