Drain Issues

[welfordnremt]

I have searched around the Internet and can not find a answer to why the toilet closest to the septic tank will not flush after a heavy rain, but the tubs and sinks in the house drain fine. The toilet furtherest from the septic tank will quit after a few days of heavy rain.

Why does the tub still drain without issue?

[HayZee518]

sounds like you don't have a stack vent. the sink and tub both have an overflow that admits air to assist with draining the waste line. if your toilet had a vent then draining the pot would't be a problem OR it has a vent but the line is clogged

[Redwood]

I'd expect that you have a failing septic system and the pipe is filling with water.

[welfordnremt]

I'd expect that you have a failing septic system and the pipe is filling with water.

I suspect the same thing, just trying to figure out why everything drains without issues, except for the toilet.

[Redwood]

The vents on the toilets are lower and will flood first as are the drain lines....

[mrcaptainbob]

Floods

Could it be because the flush of the toilet introduces a volume of water higher than what a clog would allow to 'quickly' pass? Versus the draining of a tub or sink would allow a the draining of a lesser volume? (Not to mention the passing of any solids and such....through the partialy clogged drain, that is..)

[Redwood]

Exactly! mrcaptainbob

When the drain stops flowing things get ugly from the lowest point to the highest point....