Good afternoon,
Ran into an issue today that has me a bit stumped. Remodel was done a couple years ago in the kitchen and sink moved far enough away from it's original location that I ran a separate vent line up the wall and into the attic. I put an AAV on it as this was in the winter, and I told myself I'd get around to cutting the vent through the roof come spring. That hasn't happened. The drain line ties into the old sink drain line in the basement, maintaining proper slope & size. There is a dishwasher that drains into the sink drain as well, using a high loop.
Haven't had any issues until today, dishwasher was running a drain cycle and I was using the sink, drained a couple of pots of water into it and then suddenly it backed up with some fine air bubbles coming up out of the drain. I figured something must be clogged, so I took apart the p trap which was clear. I snaked a couple of clean outs in the basement which were clear as well. This got me thinking about the bubbles that has come up through the drain so I decided to go up into the attic and check the AAV to see if it was airlocked. Couldn't get it off and remembered I had spilled a bit of glue on the threads and told myself I won't worry about as I'll just be cutting it away anyway come spring in a few weeks (doh). So I drilled an 1/8th hole right below the AAV and ALOT of air came out under pretty good pressure. Proceeded back downstairs and the sink was clear and is now working again.
What I can't figure out is how that much pressure built in the line. The only fixture serviced by that vent is the sink/dishwasher, which is 1 1/2". Now that I've drilled the hole in the pipe I'll just run the vent out the roofline this weekend (probably) but still has me wondering what happened, and why now? Does a dishwasher by nature always push some air with it and since I don't have an airgap and the sink had a decent amount of water in it, the air that normally just bleeds out through the drain instead followed the vent ? Seems unlikely as the dishwasher drain is tapped well above the P-Trap but at this point I'm at a bit of a loss. We have 1 bathroom and a washing machine but those weren't in use at the time, and all of those are tied into the main vent that straight shots up out the other side of the house so seems highly unlikely anything there caused it, and those other fixtures are all working fine.
Apologies for the long question and bit of rambling.
Thank you
Ran into an issue today that has me a bit stumped. Remodel was done a couple years ago in the kitchen and sink moved far enough away from it's original location that I ran a separate vent line up the wall and into the attic. I put an AAV on it as this was in the winter, and I told myself I'd get around to cutting the vent through the roof come spring. That hasn't happened. The drain line ties into the old sink drain line in the basement, maintaining proper slope & size. There is a dishwasher that drains into the sink drain as well, using a high loop.
Haven't had any issues until today, dishwasher was running a drain cycle and I was using the sink, drained a couple of pots of water into it and then suddenly it backed up with some fine air bubbles coming up out of the drain. I figured something must be clogged, so I took apart the p trap which was clear. I snaked a couple of clean outs in the basement which were clear as well. This got me thinking about the bubbles that has come up through the drain so I decided to go up into the attic and check the AAV to see if it was airlocked. Couldn't get it off and remembered I had spilled a bit of glue on the threads and told myself I won't worry about as I'll just be cutting it away anyway come spring in a few weeks (doh). So I drilled an 1/8th hole right below the AAV and ALOT of air came out under pretty good pressure. Proceeded back downstairs and the sink was clear and is now working again.
What I can't figure out is how that much pressure built in the line. The only fixture serviced by that vent is the sink/dishwasher, which is 1 1/2". Now that I've drilled the hole in the pipe I'll just run the vent out the roofline this weekend (probably) but still has me wondering what happened, and why now? Does a dishwasher by nature always push some air with it and since I don't have an airgap and the sink had a decent amount of water in it, the air that normally just bleeds out through the drain instead followed the vent ? Seems unlikely as the dishwasher drain is tapped well above the P-Trap but at this point I'm at a bit of a loss. We have 1 bathroom and a washing machine but those weren't in use at the time, and all of those are tied into the main vent that straight shots up out the other side of the house so seems highly unlikely anything there caused it, and those other fixtures are all working fine.
Apologies for the long question and bit of rambling.
Thank you
