constantly draining toilet bowl

[plumbingdummy]

Hi all,

My toilet bowl constantly drains until it is almost empty. I am wondering if this is caused by a clogged vent, or by a faulty toilet, or both.

The following description includes a second problem (tank & toilet bowl won't refill), which I am NOT trying to solve at this point.

The toilet is a Briggs Vacuity Vacuum-Assist 4210 which I acquired in 2005.
According to Consumer Reports (Oct. 2002), the vacuum chamber inside the tank "helps pull water and waste down the drain. . . . Vacuum-assist toilets use the same kind of early-closing flush and fill valves that gravity-flush toilets do."

Soon after the toilet was installed, I found the tank and toilet bowl usually would not refill after a flush unless I nudged this little part inside the tank. Remedies by two different plumbers worked for only a short time. (This is not the problem I'm trying to solve now.)

The bowl-draining problem started much more recently. Here is the routine I've been going through to deal with both problems: Water supply to toilet is kept off to prevent wastage. To use the toilet, I turn the water supply on, then nudge the thing inside the tank to refill the tank and toilet bowl. Right after the flush, I turn the water supply off. After that usually there's gurgling that goes on for some time.

Lately it's gotten worse, in that so much water is flowing out of the bowl while the toilet is in use that I have to nudge the thing inside the tank a second time to refill some more before flushing.

Also, when water drains from the bathroom sink, it sounds a lot different than it used to--louder I guess, and the sound seems to be coming from the bathtub drain.

The reason I'm wondering if the toilet could be contributing to this is because of the vacuum assist. However, according to a "Guide Book on Home Plumbing" I have, without a vent, trap water siphons off. I'm wondering if a clogged vent could allow a vacuum to develop which would draw water out of not only the trap, but the toilet bowl. However, there is no smell of sewer gas, and there is always a very small amount of water in the bowl.

Do I need to get the vent cleaned out, or replace the toilet, or both, or what?

 

[PioneerPlumber]

I'd pull the toilet and check for any obstructions in the toilet and closet bend. Run lots of water at other fixtures and look into closet flange to see if it fills with water. If that's ok, go to the roof vent and look down using a mirror to direct the sunlight into the pipe. Look for any obstructions. Maybe put the toilet onto a bucket and fill the bowl with water. See if it siphons or possibly leaks water out of the bowl somehow. You can use a flashlight and look under the toilet maybe. Or maybe add food coloring to the water.

Sounds like you simple need a new toilet. No crazy pressure assist crap. Just a good ol fashion tank style toilet.

 

[plumbingdummy]

Thanks, Daniel.

" check for any obstructions in the toilet and closet bend." Do you mean that obstructions could cause draining? This seems counter-intuitive to me--but I'm pretty ignorant about plumbing.

Also, you referred to "pressure assist"; but this is vacuum assist, which is the opposite.

 

[phishfood]

My first thought is that you have a clog in the drainage line serving the bathroom. I would start by having the drain line properly cleaned via the toilet flange after the toilet is pulled.

 

[plumbingdummy]

I am going to be calling a plumber tomorrow.

Can somebody explain how a clog in the drain line can cause draining of the toilet? There is no problem with flushing--i.e. it goes down properly, as far as I can tell.

There was an earlier incident, a couple of years ago, before the "draining" problem started, when upon getting up in the morning I found the bathtub filled to overflowing (it's lower than the toilet) and the toilet running constantly. I turned off the toilet water, and called one of the "rooter" businesses. They were just starting to get up onto the roof to clean out the line through the vent, when suddenly we heard, through the vent, all the water very quickly draining out of the tub. They did nothing further, and that was the end of the problem.

Except that's when I started keeping the toilet water turned off.

 

[phishfood]

Have the toilet pulled, and the line snaked THROUGH THE TOILET DRAIN. Going through a 2" or 1 1/2" roof vent does not allow for a large enough cutter head to thoroughly clean the line. Make sure they use a head almost as big as the inside of the drain line at the toilet. Anything less will leave stuff in the line and cause a blockage again in the future.

 

[plumbingdummy]

I called a plumber that specializes in snaking. They ran a lot of water and determined that there was no blockage. They diagnosed the problem as a faulty fill valve and flapper, which they replaced, and that seems to have solved both problems: the bowl constantly draining and and the tank not refilling.