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drumz 07-10-2011 12:52 PM

Toilet flushes by itself
My house was built in 1949 and we have a septic system, gravity fed. When the pump comes on which pumps the crap to the septic tank the toilet flushes, it is below the toilet in the basement and they share the same vent. My feeling is that it is a clogged vent pipe so I got on the roof and tried vacuuming it out with my shop-vac by shoving the tube down as far as I could (about 6 feet) and then took some fish tape and running it down to try to loosen anything while sucking. I did get some stuff out because I have a lot of pine trees and the vent stack is a 2 1/2 incher so it could collect debris. I have since covered it with a wire mesh but I still have the problem.

Does anyone know of a situation like this that could impart some wisdom? I hate the smell when the toilet empties like that!

Thanks very much.

Redwood 07-10-2011 02:49 PM

Okay, if you have a pump the septic or, at least a portion of it is not gravity...

I would suspect as you do a blocked vent or, the float switches on the ejector pit being set improperly where the line foor the toilet is flooded then when the pump comes on the toilet is sucked dry because the higher than normal level interferes with the venting...

Additional troubleshooting is required and flooding of the drain for the toilet should not occur...

drumz 07-10-2011 03:59 PM

Gee ya got me on that one, it is NOT completely gravity fed, I confess, sorry for being so misleading /snark off :p.

Really though, thanks for taking the time to respond.

Now from what I can tell you are saying something about a level that is obtained in the transfer pump station (sump pump? not sure what to call it, please don't hit me) that is somehow drawing from the toilet because it is too high. Hmm, I have never opened that up since it's sealed and there is only one pipe coming out of it that I can see, but maybe there is a float in there and if it's like the ones in a Ford PU, they can get a hole in them and they end up sinking giving a bad reading or in this case triggering the pump later than it should because the level is too high rising above the vent... is that what you mean? It sounds plausible but I have to see a drawing to get a better idea of how to combat the problem.

I'm going to go take a good look at it and get a name and maybe find a septic forum and try to figure out where they vent it and if there's a float, yada, yada, yada. Maybe I can blow the vent out if the problem ends up being a clog?

Thanks for your help!

Redwood 07-10-2011 04:25 PM

This diagram should help explain the proper levels in a sewage ejector pit....

You may not have an alarm but it the inlet pipe is flooding the pit emptying can cause the toilet to empty...

The inlet would be right above the level where the alarm turns on...

drumz 07-10-2011 05:13 PM

I do have an alarm on it so shouldn't the high level trigger it?

Would blockage be the issue or maybe the float is not floating?

I guess it's under the cover...

Here are some pics:

Redwood 07-10-2011 05:19 PM

You may have a rubber grommet that can pull out where the wires enter and you can shine a flash light in and make sure the float switches are clear and clean then watch the waste water level while you run water to see it cycle.

If it seems to cycle properly then look for the clogged vent....

Try to avoid pulling that cover unless you see something wrong...

Trust me it will take a few days for the smell to depart the sinuses...

drumz 07-10-2011 06:27 PM

I'll put a clothespin on my nose.

Thanks for the tips!

TxBuilder 07-11-2011 10:15 AM


Originally Posted by Redwood (Post 58684)

Trust me it will take a few days for the smell to depart the sinuses...

And if you're like me, you can even taste very strong smells. Yuck!

slownsteady 07-11-2011 02:06 PM

You didn't say how tall your vent stack is. Six feet of shopvac hose doesn't seem near long enough to reach a clog, which may be down by the pump. And a fish tape isn't going to clear it.

Redwood 07-11-2011 04:06 PM

I do recommend professional grade equipment preferably with a seasoned expert attached to it for any drain cleaning job...

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