Why is Water Backing up Into My RV's Bathtub/Shower Drain?

by Mark G.
(The Woodlands, Tx)

Why Water is Backing up Into Your RV's Shower

Why Water is Backing up Into Your RV's Shower

I have a new 2014 Gulfstream Kingsport 26.5 We were only on our second weekend outing and we noticed Saturday night that the bathtub drain seemed clogged (was running water into the bathroom sink and it came back up through the tub drain) My wife has long hair but I can't imagine that it's getting clogged after only 3 showers?

Tried some baking soda and white vinegar and it seemed to clear a bit and drain... After towing it home to storage and checking it again, it wasn't draining... Going to call The dealer that I bought it from this AM and ask some questions but I thought I would post here too.

MDG in the Woodlands

ANSWER: Hi Mark I think that I am going to be the bearer of good news. I do not believe that your new Gulf Stream travel trailer bathtub drain is clogged I think that you need to dump your Travel Trailers gray water holding tank. The first thing that you should check is the monitor panel in the RV and look at the grey water holding tank level and I am pretty sure that you will see that it needs to be dumped (can't blame your wife's long hair on this one).

The fact that you said that you had taken 3 showers and never mentioned emptying the grey water tank is a pretty good indicator that your grey water holding tank is full and should be dumped. The grey water holding tank on your particular RV holds a total of 37 gallons of wastewater and it will fill up quite quickly especially if you choose to take long showers.

You also mentioned that the water started coming up the bathtub drain when you were running more water in the bathroom sink; that also indicates that your holding tank is full. When you were running the water in the sink there was no more room in the tank so the water started to come out of the lowest drain in the gray water system which in most cases will be the bathtub or shower drain in an RV.

Good Sam Extended Service Plan
is mechanical breakdown insurance for your RV, 5th Wheel, Trailer, and Tow Vehicle! FREE Quote

by the way, do not feel bad about having this happen to you because I can guarantee that you are not the Lone Ranger in having this happen. It has happened to me and I guarantee that it has happened to a lot of other RVers who may not be as willing to admit it.

A good rule of thumb when at a campground is to make it a habit to check the Grey and Black water tank levels on a daily basis and dump them when they reach the 3/4 full mark. Also, a reminder here: even though you are hooked up to a sewer system when at a campground you should not leave the dump valves open as letting the water drain out and not the heavier waste solids can cause problems with your waste holding tanks in the future.

If you are sure that your grey water tanks are empty and your shower is still backing up, you might want to check the plumbing vents on the roof of your RV. If the plumbing vents on your RV are blocked, the water in your RV will not drain properly.

Special Note: As much as I hate to say it you should not trust your RVs holding tank monitors reading. Unfortunately, RV Holding tank monitors are notorious for being inaccurate. So even if your monitor is not showing that your tank is full, you should still dump them and see if that solves the problem. To learn more about fixing your RVs tank monitor, you should read my article How to Fix an Inaccurate RV Holding Tank Monitor.

Another good rule of thumb is to dump your waste holding tanks before leaving a campground so that you have clean tanks and less weight to haul around.

I hope that this information has been helpful to you.

Do you have any suggestions or comments on this topic? You can add them to this page by clicking on the "Click Here To Post Comments" link located near the bottom of this page.

Happy RVing

RVing Al

Comments for Why is Water Backing up Into My RV's Bathtub/Shower Drain?

Average Rating starstarstarstarstar

Click here to add your own comments

Rating
starstarstarstarstar 		water backing up in shower and sink
by: Ruben Duran

shower and bathroom sink were backing up, i tried everything, change vent valves, draino, flushing all pipes nothing worked, i finally called thor, btw i have a 2016 tuscany 40DX. they suggested i raise the vent valves under the kitchen and bathroom sinks, works great now, hope this helps someone
Rating
starstarstarstarstar 		Is my gray water not draining?
by: Anonymous

My 2001 Gulf Stream seahawk shower not draining. It doesn’t have indicator panel. Only has one dumping valve. Is my gray water backing up?
Rating
starstarstarstarstar 		Bathtub Backup Solution??
by: Rachael from Colusa County California

I purchased a 1998 Fleetwood Mallard about a year ago, and have been dealing with this backup issue for the past year as well, only I knew to dump my tanks. However, dumping the tanks was not helping. Online the only advice was I should level my trailer or check my vents. I did both. Nothing helped. Finally, a friend of mine who also knows nothing about RV's crawled under the trailer and noticed my grey tank, in comparison to my black tank, was bulging. So he cut into the pipes leading to my grey tank and out came the foulest, obnoxious smelling "stuff" I had ever beared witness to in my life. Almost a full 10 minutes it poured out. So something was blocking the exit from the tank, and most likely still is, as my panel still reads the tank as 2/3 full. So before a future episode WHAT CAN I DO? Is it possible the open/close valve itself? Or something worse? Will I have to replace the entire tank? Please help...
Rating
starstarstarstarstar 		Drain
by: Anonymous

Water comes up in my bathroom drain also. My grey water take is empty. What can I do?
Rating
starstarstarstarstar 		any other solutions?
by: question 1

When running water in the bathroom sink, water starts coming out of the tub drain. My gray water tank is empty. Gray water flush valve is closed. Vent pipe is clear. Are there any other suggestions I can try?
Rating
starstarstarstarstar 		Back up in shower
by: Anonymous

Thank you so much for advise we were able to figure out this problem after reading the comments. It was a great help. Thank again
Rating
starstarstarstarstar 		My sink water is going in my tub to!!!!!
by: Caligirl707

Hi I love this post I tried almost everything my tub started to plug up and now kitchen sink water is coming up in tub I went on roof and there's 3 vent holes idk which 1 is for water I did backing soda vinegar hot water plunger and hard plastic with hooks tank is drain Help please oh and its a 50 ft 5th wheel Tenton 1987
Rating
starstarstarstarstar 		Water backup in the shower
by: Chris

My water lines inside my rv froze I still don't have running water but water filled up my shower and overflowed in the bathroom. Why is there water in my shower if I can't get water out of my faucets.
Rating
starstarstarstarstar 		Help drain
by: Help

Why is my sink water going into my tub I brought this 98 fleetwood bounder 3 yrs from a family it was draining slow but I do not know how to find the problem what should I do
Rating
starstarstarstarstar 		Clogged tub
by: Anonymous

I have 2003 camper my tub I pulled all kind of globs of hair out of it it's still clogged up water is full in tub it's still not draining I'm sure there's more hair where I can't reach please help me
Rating
starstarstarstarstar 		bathtub drain
by: cdc43

I was just finishing a shower (95% done) and approx 1 inch of water remained in drain. Sometime overnight, it did drain. I did the following to investigate. Water drains from sinks to grey water tank.

1. back flushed grey tank
2. checked vent stack by dropping a plumbob from roof to tank bottom - clear to bottom
3. removed and cleaned tub trap
4. snaked the drain from trap to grey tank
5. flushed vent stack from roof with hose - water went into tub???

Please any other ideas.

Thanks
Rating
starstarstarstarstar 		plumming backing up water in shower
by: cynthia

I have the same problem with the water backing up in the shower when doing dishes and both drain out valvea are open and empyed out where is the clog help
Rating
starstarstarstarstar 		i dont assume
by: thinking

the vent on roof could be plugged, even just partially or too small. So when water drains in say the bathtub it pushes air down ahead of water and that air needs to go somewhere. That air then pushes back up another drain if it cant all go up vent to roof. When it pushes back up say the sink drain it pushes all the water in the trap ( the u in the drain pipe ).

RV manufacturers are not known for quality workmanship or logical designs. Its all about making it cheap and light weight. It is very possible they left scrap material or garbage in vent pipe and it is also possible the pipe was designed too small. There is also other ways it can get plugged such as bugs or over filling tanks and causing something to go up vent pipe.

Go up on roof and you can remove cap on vent pipe. Use logic form there to see if it is plugged. The line should be at least 1-1/2" inside diameter. Any less and it could be a design flaw.
Rating
starstarstarstarstar 		Why is Water Backing up Into My RV's Bathtub/Shower Drain?
by: Mark G

That was the first thing I did wasa empty the gray tank.... it still wont drain...
Rating
starstarstarstarstar 		Yes, don't fell bad.
by: Anonymous

When you have lived your whole life in a stick house it can be hard to wrap your head around things required for a rig that happen automatically in a house. Be glad you first learning experience was with gray water. For many of us, it was with black water. (Mine was on the importance of making sure the hose connector is properly seated each and every time you dump and open the grey water first, just in case.)

Note From RVing Al: You may want to read our article How Not To Dump Your RV Holding Tanks to find out how much worse it could have actually been. :-)

Click here to add your own comments

Return to Ask an RV Question.

LEARN HOW TO RUN 2 RV A/Cs ON A 30 AMP CONNECTION