question for the plumbers

i know there are a couple of plumbers around here. if you have a moment to educate me, i’d really appreciate it!

Today our basement toilet just randomly started gurgling and the bowl drained almost completely. This didn’t happen after a flush, and we weren’t actively using any appliances or sinks or tubs etc at the time. Finding the bowl empty, I flushed it, which went fine, and it re-filled as normal. Since then I’ve flushed it several times, no issues.

I just installed this new toilet about a month ago after a bit of a nightmare — we came home to find standing water all over the basement, and the toilet bowl was empty. The water was fresh clean water with no smell, not dirty stuff that backed up. I replaced the toilet after that incident because the toilet was VERY old.

To me the symptoms would seem to suggest a blockage in the vent stack created negative pressure that sucked the water out of the toilet trap. Maybe a snow situation up on the roof, going to investigate that tomorrow. But still I’m confused — why would just that one toilet be affected? And why just that one time? I figured if we had a vent stack blockage we’d be seeing issues all over the house, consistently — and probably smelling sewer gases as well? None of that is happening, the issue seems random and isolated.

If it matters: ranch House built in the 50’s in St. Paul. Every appliance, tub, sink, toilet, etc is draining quickly and efficiently as you’d expect. There are two bathrooms, one on the main level and one in the basement, and they are directly over/under one another.

THANK YOU!

Duplicate post*

Vent is froze from all the cold, wind and snow. Hopefully it will thaw out with the warm weather coming

Coletrain27 wrote:

Vent is froze from all the cold, wind and snow. Hopefully it will thaw out with the warm weather coming

Thanks for the reply. Can you briefly explain why this would only create one single symptom at one time, as opposed to consistent house-wide issues?

The leaking toilet just sounds like a toilet seal leaking. Most things have traps on them that will prevent them from smelling like sewer gas unless they are not used for a very long time and the water in the trap evaporates.

Coletrain27 wrote:

The leaking toilet just sounds like a toilet seal leaking. Most things have traps on them that will prevent them from smelling like sewer gas unless they are not used for a very long time and the water in the trap evaporates.

Yeah I figured the big flooding event we had was a separate issue, some kind of a malfunction on a very old toilet with a bad seal, etc.

But I’m still confused why only one toilet in the whole house would gurgle if the vent was clogged?

Not sure on that

Could have its own vent

Thanks coletrain.

And Munchy, that’s an interesting thought. I’ll look into that more, thanks.

We just had our bathroom remodeled and I experienced something similar today. They ran a new stack which connected our toilet and tub venting….flushed the toilet and the tub gurgled. Went out back to check the vent pipe on the roof and it was blocked with snow/ice Cleaned them up and have not had an issue. Hope your fix is an easy one.

Blocked vent. Same thing happened to me during the cold snap.

Couple remedies for frozen vents are to hang a piece of copper in them or increase vent pipe size to 4 inch where it goes through the roof. Heat tape will also work to thaw vents but it’s also a very good way to melt the pipe or burn the house down.

Soundslike this issue could possibly be a partially clogged drain pipe to.

Mike W wrote:

Soundslike this issue could possibly be a partially clogged drain pipe to.

A lot of what I read online suggested that as well but my non-plumber mind just doesn’t get it. Everything is draining quickly as you’d expect. And we weren’t trying to drain anything at the time either. This is all confusing to me but if there’s an easy way to explain why you think a drain clog is at play id sure appreciate it!

Thanks again!

munchy wrote:

Could have its own vent

I see two vents up on the roof. One is placed almost directly above the two bathrooms (north side of the house), and one is placed atop the kitchen (south side). The one on the bathroom side is 6-8 inches above the snow line, and the one on the kitchen side only has an inch or two.

That can also happen if they’re jetting/vaccing the mains in the street and vents are plugged?

fishtoeat wrote:

That can also happen if they’re jetting/vaccing the mains in the street and vents are plugged?

Haven’t see any action from the city water trucks in our neighborhood recently, but that is a possibility.

Welcome to the club. Have a similar issue at my cabin. Can tell right away when I walk in the cabin if my vent pipe is froze. It smells like poop. We have a holding tank and there is also a vent pipe by the holding tank. If the snow covers the vent by my holding tank, the pipe on my roof seems to freeze up more often. On Monday my roof vent had a snow cone on top of it and was froze. I shoveled off the holding tank vent and when I looked an hour later, the roof vent didn’t have the snow cone anymore. I also have noticed the basement bathroom has the stink when the vent is froze way more than any other fixtures. Unfortunately, it is a PITA for me to reach the roof vent to unplug it.

Mike, could u elaborate on hanging piece of copper in the vent pipe to prevent freezing. Thanks in advance

dirtywater wrote:

Today our basement toilet just randomly started gurgling and the bowl drained almost completely. This didn’t happen after a flush, and we weren’t actively using any appliances or sinks or tubs etc at the time. Finding the bowl empty, I flushed it, which went fine, and it re-filled as normal. Since then I’ve flushed it several times, no issues.

fishtoeat wrote:

That can also happen if they’re jetting/vaccing the mains in the street and vents are plugged?

This is where my thoughts were too. Our basement toilet will do the same when the city jets the main under the corner of our home, and I mean the actual corner.

I’m with Mike on this one. It certainly could be a frosted shut vent terminal, but what you are describing sounds a lot like a clog. If you had an obstruction in your building drain(under floor piping) or sewer lateral that suddenly let loose and drained it would almost certainly siphon your lowest fixture. Now this is assuming a soft obstruction that didn’t completely stop drainage as you didn’t mention sewage backing up out of your floor drain. If it was an obstruction, now to find out what caused it. A call to a drain cleaning service may be in order. A reputable contractor would camera your drain first to identify any issues such as: wet wipes, toilet paper, some type of foreign object, tree roots, rotten piping, etc..

I have never used one of these but have heard they work.
https://sewerskewer.com/

Thanks everyone. It happened last night again, just after my wife released a bath tub full of water down the drain. That to me says venting issues but I’m going to have both the vents and the drains checked out.

If someone could explain to me how you have a clogged drain issue but every single appliance, sink, tub, toilet all drain quickly and efficiently, I would love to try to understand this. I don’t doubt the diagnosis, but don’t understand it either. Wanna learn!

Like I posted, I’m not ruling out the venting issue but, a frosted shut vent usually causes slow draining issues.

The type of clog I am talking about is usually caused by tree roots grabbing paper causing a soft obstruction. Effluent will build up behind the clog, when a large amount of water is released the air in the pipes has nowhere to go but back upstream causing the gurgling in the toilet that you described. Now when enough head pressure builds up the soft obstruction will release and syphon the water from your toilet bowl. The pipe could be just partially obstructed which would allow your slower draining fixtures to drain normally, but when a large amount of water(toilet/bathtub) is released the air is forced back upstream.

Didn’t you just say the bath tub caused the issue again? Sink or toilet don’t use nearly as much water as a bathtub. Partially clogged drain is causing issues with the vent. Warm temps the last few days most likely took care of any frozen roof vents. Just about any temps above zero unthaw most of them.

Yes, the toilet gurgled and emptied shortly after draining the tub 2 days ago. Yesterday drained a full tub again and no problems withe toilet.

Would you guys recommend something like Zep Root killer in that toilet, or is a partial clog that far down only something a plumber can deal with?

Our vent opened up yesterday morning and that toilet flushes normal again. Happens every winter when it’s cold, and we have a big snow build up on the roof where the vent is. If I hear the tub drain gurgle when flushing toilet, I know vent is plugged and just turn on the tub faucet for a couple of seconds. Nothing wrong with the drain or septic.