I need help, or at least advice. I run an RO/DI system because I have saltwater tanks. This system is set up so I only use it when it's time to make water. Recently, while making water, the drain in the bathroom downstairs (where the unit is) started backing up and flooding the bathroom while making water. We assumed the sewer line was clogged. My sister in law is also having sewer line issues so they were going to route out their line and then come do ours, which is why I didn't call a plumber (well, I did but I was told to cancel).

Now on to the weird part. We have avoided making water for the tanks because of the flooding issue. We assumed it was the waste water line that we have going into a drain in there that was producing all of the water backup. Yesterday we desperately needed to make water so re-routed the wastewater line into the backyard. So no water going into the drains in the house.

This morning I get up and the bathroom has again flooded. I also look outside and I realize the spigot in the back is spurting water. I tried to turn it off but I only made it worse. We just replaced that spigot last year for leaking, so it is fairly new. I also have noticed that the water coming up from the bathroom drain is never sewage (flushing toilets doesn't seem to cause any issue, but a long shower will) but clean water.

I don't know what is going on, if it is indeed roots in my system like I assumed? I know at this point I need a plumber. I just want to have a general idea of what to say and where to point the plumber when they come. I don't really know much about plumbing and I don't have a dedicated plumber that I know and trust. I'm assuming they're like mechanics - most are okay but there's always the one who tries ....



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if a long shower causes a back up but the water backing up is clean, that makes no sense??? (i'm not being critical just trying to rationalize)

do you have an upstairs toilet that may be running ? this would cause clear water to back up.
a condensing furnace could also cause this..
just a couple of guesses...

It doesn't make sense because we never get sewage in the backup, just clean water when we take long showers and run the RO/DI system. And it backing up this morning didn't make sense because we didn't have anything going into the drains TO backup.

The toilets are not running, either. I thought it was the sewer line but how does it back up when nothing is going in?

so, where just exactly is the water coming back into the bathroom?
is it coming from under the toilet? this would be the lowest point in the system.
could it be ground water backing up thru a cracked underground pipe?
is the ground level outside higher than the floor level of the bathroom that floods?
is there a basement below with a washing machine connection?

Call the plumber and get it evaluated and resolve. You will have peace of mind and a sewer line that works as designed. You've had some nasty rains in your area this week.


Best Wishes

it's coming up through the shower drain. It's on the bottom level of a tri-level house so yes, lower than the ground outside. Nothing comes up through the toilet - the toilet water level actually stays pretty low.

just venturing a wild guess... it does seem as though it is ground water. just why it comes up thru the shower and doesn't flow away could mean there is a partial stoppage somewhere. this too gives a slight clue as to why long showers cause some interior flooding.
i'm gonna go out on a limb and say have the sewer main professionally cleaned. this won't stop the infiltration of ground water into the sewer pipe but at least the water will flow away from the house.
the person who cleans the sewer main should be able to offer some more advice.
post back with the results and ask questions here before agreeing to any additional work.

Flush the toilet while the water is backed up and see what happens.