This is my only post of the day today because of my plumbing issue, complicated by the fact that I was scheduled to work in the emergency room 9-9 today, until my boss called me at 8 o’clock and rescheduled me to work 1 pm to 1 am today.

For six years running, we have had a plumbing problem. I have been suspecting it was a vent problem. It rears its head every fall and spring. We have had three different plumbers out, and I swear it has cost us thousands of dollars, and no solution has been found. The problem corrects itself after a day or two, so by the time a plumber gets here, they never find anything, but are happy to bill us between $100 and $500 to tell us nothing is wrong. Assholes.

The last plumber to come out (4 months ago) thought I was nuts when I asked him to check the vents. He found two large frogs living in one of the vents. That cost me $200. Other than that, nothing has ever been found. They even put a camera through my pipes two years ago. Nothing was found, but they still billed me $500.

Let me describe the drains in my house: There are two vents in the house: one over the laundry, which shares a drain line with the kitchen. The second vent is over the guest bathroom and shares a drain line with the master bathroom. There are three undersink vents that are covered by air admittance valves.

We are planning on moving next year and converting this house into a rental. If this plumbing issue keeps up, I may just sell it, even though the wife doesn’t want to.

Anyhow, time to get ready for work. I am not looking forward to getting off at 1 am.

Categories: Me


Jonathan · April 21, 2022 at 12:18 pm

Definitely sounds odd and frustrating. Makes me wonder if it’s connected to changing atmospheric conditions, especially the door opening part.

Have you checked your vents are working properly, especially the undersink vents? Replacing them would be a cheap troubleshooting step. Note that the vents “should” be at the high point in the system.
Also, do you have the right size pipe everywhere?

Steve S · April 21, 2022 at 2:15 pm

Have the AAV’s been replaced? Cameras won’t detect a malfunction there.

Divemedic · April 21, 2022 at 3:24 pm

Yep. Replaced all 4 aav in the house

    Matthew · April 21, 2022 at 8:47 pm

    Holy smoke, you’ve got 4 Amphibious Assault Vehicles? I’ve done some moderate prepping but that’s gilding the lily a bit.

    So, you have 2 plumbing vents to the atmosphere from 2 separate drain legs that merge at some point into a single sanitary outlet?

    If there is clean-out for the outlet, either interior or exterior, crack that thing open the next time you have a problem and see what happens.

      Divemedic · April 22, 2022 at 9:03 am

      Nothing. It’s clear.

        Matthew · April 23, 2022 at 8:57 am

        I was just thinking some sort of pressure equalization or vapor lock thing.

        Still thinking it’s a venting issue.

        Years ago I had wasps in a vent line, went up on the roof with a can of raid, a piece of chain on a string and a garden hose.

PapaSierra · April 21, 2022 at 7:45 pm

Can you post a sketch of the plumbing system?

It can’t be solely wind related. The wind never blows consistently in one direction for hours, let alone for days.

The only thing that happens every fall and spring is the change in temperature, of both the soil (where the pipes are located) and the air. Can you check your past bills to see when you had plumbers visit? You could cross check those dates against Accuweather’s website that’s shows daily highs/lows temperatures going back two years. But you don’t get freeze/thaw cycles, right? So that’s probably a dead end.

This is only partially relevant, but if there’s an obstruction in the pipe, and a blockage is formed that consists only of toilet paper and human waste, the blockage can be degraded by the water and eventually clear itself. If your blockage was “hanging on by a thread” after two days then opening the door might have been enough to bust it loose. But if this is the case then it would be independent of the seasons.

PapaSierra · April 21, 2022 at 7:57 pm

You said “In one of the bathrooms, the toilet occasionally doesn’t flush. If you try to use a plunger, the toilet doesn’t drain, but you can hear gurgling in the 2 sinks and the shower in that bathroom, and this gurgling comes with a smell of raw sewage.”

A few questions:
– When this occurs, does it always start with a heavy “load” being flushed?
– Does the “smell of raw sewage” present itself only while plunging the toilet? If so then this would seem to indicate that the blockage is downstream of the sinks, as the plunging action forces air out the AAVs under the sinks.
– Do the sinks and shower flow freely while the toilet is plugged?

    Divemedic · April 22, 2022 at 9:05 am


      PapaSierra · April 22, 2022 at 8:40 pm

      We’ll that’s just mean. You’ve exhausted my plumbing knowledge. I’m out. Sorry.

        Divemedic · April 22, 2022 at 10:20 pm

        Only thing left to do is call it a day and have a beer. Or three.

TechieDude · April 22, 2022 at 8:07 am

This smells of a venting problem.

I’m not a plumber, but I play one on TV.

Seriously. My daughter bought a house where they moved the drain to the washer, which happened to have the vent for the kitchen. Nothing but misery. So they went to the seller and had him fix it. The plumber came out, rebuilt the drain and put in an AAV.

Then what happened was intermittent misery, like you have.

It all started working when I came out, removed the AAV and ran a piece of PVC to the attic and out where the old vent was. Here’s the rub – behind the wall to the washer was wide open space around where the gas fireplace was venting. Easy as hell to put in the vent.

My guess is you have one or more AAVs, probably more, that fail and when you open the door they kick loose. A proper test would be remove them one at a time when the situation is happening.

Or you could vent the pipes to the outside, properly, as God intended.

    Divemedic · April 22, 2022 at 9:07 am

    Removing an AAV allows the toilet to flush and work normally. Replace the AAV, and the problem resumes. If we do decide to move to another house and convert this to a rental, getting the bathroom pipes vented will definitely be considered.

Chris Mallory · April 22, 2022 at 11:04 am

“they never find anything, but are happy to bill us between $100 and $500 to tell us nothing is wrong. Assholes.”

Still cheaper than going to the ER and being sent home with no treatment other than “Follow up with your PCP.”

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