Plumbing vent clogged

gary83

I've noticed a sewage smell particularly around the second level of a three story townhouse for a while, after ruling out the other half, faulty extractor fans and fairly positive it wasn't me I've got it narrowed down to a clogged plumbing vent. The reason Im convinced its the plumbing vent is the top floor bathroom basin in particular makes a loud gurgling sound when emptying & if you flush the top floor toilet and watch the water level in the middle floor toilet then you can see it drops slightly as the water is suctioned out.

The vent pipe is relatively easily accessible in the loft and is topped with an AAV Valve, obviously it's impossible to see anything with the naked eye, I can fit a plumbing snake down the gap & have tried that along with a couple of litres of water which has improved the situation but not completely, the snake comes back with only slight evidence of a soft blockage. any other remedies I could try? Other than more elbow grease with the snake or a garden hose, which I'd probably rather leave as a a last resort.

southcoastrgi

You shouldn’t be able to smell anything, it sounds like your durgo valve (aav) has failed, try replacing it

gary83

southcoastrgi wrote: »

You shouldn’t be able to smell anything, it sounds like your durgo valve (aav) has failed, try replacing it

Thanks for the answer, I'd ruled out the valve failing and was leaning towards a blockage as I removed the top moving part so air was definitely getting in and tested the drains again, still had the same issue unfortunately so I didn't think replacing the valve would help?

EssexExile

It's an air admittance valve, it's supposed to let air in but not out. Without it or if it's faulty the air & smells get out, with it working they don't. If you've got a blockage you'll get a flood.