# toilet overflows when flushed right after a shower



## Jpc1225 (Aug 3, 2010)

This has happened twice in the past two months. When we run too many water appliances at once (dishwasher, laundry, shower, etc.) we will start to get gurgling in the pipes. Shutting off one of the appliances stops the gurgling. Lately when I have taken long showers, the gurgling starts again, even if nothing else is running. The gurgling happens to both toilets. Whichever toilet we flush right after a shower is the one that backs up, naturally. toilets do not overflow other times we flush - just when we've added a lot of water to the line immediately prior.

We have suspected a clogged septic tank in the past when this happened. Septic guy cleaned out our tank but said that there was no clog. My husband has opened the tank a few times since then when the gurgling has persisted. No solids clogging, but the tank was full of liquid. 

We had a plumber come out for a different problem in January (six months ago) and mentioned the gurgling to him. He didn't think it was a septic tank issue then but I don't remember all what was said. 

Nothing backs up in the sinks/tubs. Any help?


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## kok328 (Aug 3, 2010)

sounds like a partial clog in the drain pipes or more likely the vent pipe.


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## Redwood (Aug 3, 2010)

The pipe coming into the septic should discharge into the tank above the water level of the tank. If the tank is full of water so that the inlet pipe is flooded or, it is up to the top of the tank then you do have a septic problem.

The water is not making its way across the tank and out the outlet to the leaching fields fast enough for the volume of water you are using.

There may be a few things that can cause this to happen....


Toilets with leaking flappers and dripping or, running faucets can put large amounts of water into the system. Sometimes fixing the leaks can make problems like this go away.

Doing many loads of laundry on a single day should be avoided. Instead do a load everyday rather than have wash day.

Sometimes there are weather conditions that cause high groundwater levels, When you know these conditions exist you should curtail water usage to avoid problems.

When a tank is in need of cleaning sludge and scum meet slowing the flow of water through the tank this can cause the tank to fill.

Some tanks have a filter on the outlet which can cause the outflow from the tank to slow when the filter is clogged and needs cleaning.

Lastly is the gloom and doom one where your leaching field has problems and needs repair or, replacement. This is expensive! If this has happened I would recommend keeping the existing field in place and installing a second field. The old field will regenerate after a couple of seasons of non use and be ready for use again. With alternating fields you will probably never have a problem again.

I hope that your problems are minor and this advice helps.


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## GregC (Aug 4, 2010)

Hello, Gurgling is a sign of a vent problem. The fixtures are over loading the waste lines and the vents are not able to allow enough air in to allow proper drainage. Clogged roof vents, or too small of vents per fixture. Has the plumbing been changed or update? Sometimes too many fixtures are added and not enough vents are added or over sized. A waste vent serves as 2 purposes, 1-to allow methane gas to escape and 2- to allow fresh air in to allow for proper drainage. Imagine your thumb on a straw of liquid in your drink? We have all played with that...your thumb creates a vacuum...same works with a clogged vent or a too small of a vent. Naturally when you flush or run more fixtures at once...it then gurgles even more. hope this makes sense.


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