View Full Version : Shower won’t drain

09-22-2021, 12:59 PM
I have a 2021 cougar 29fkd the shower I think had a clog I have checked the vents on the roof. I just dumped yesterday day the on command thing said it’s about half full. I have tried using a soft bristled snake and I get this brown flakey gunk that comes up out of it. When I drain the sink the sink weather goes into the shower I know it’s not full (at least I would like to think). My next plan is to use wet dry vacuum to get out as much water as possible then take the p traps out of both the sink and the shower and shove a snake down there end of the pipe. But I really open to suggestions. Thank you for your help and suggestions.

09-22-2021, 01:07 PM
Is the shower backing up? Can't quite understand what would block a shower drain. Kitchen sink might have food accumulate but the shower? How do you plan putting a snake through the drain? The drain is usually cast into a fiberglass part that is glued into the pan or at least on units i have owned. How do you get a snake into a small hole?

09-22-2021, 01:18 PM
Yes the shower is backing up. My plan with the snake is to put it threw the shower drain as when I take the metal screen off The drain it had a wide enough opening. Also side note when I fill it up the bathroom sink I can see the water bubbling back up. And if I can’t get the snake in there then I am going to take the p trap off and try that way.

09-22-2021, 01:19 PM
Don't know if this could be relevant to the drain in a camper but sometimes our shower at home gets really slow or stopped up. My wife has long hair and over time it forms a 'hair ball' in the trap. We bought a claw type device that is flexible. We can remove the drain cover and insert this down into the drain. You push a button on the t handle and 3 prongs extend and spread. Release button and they retract and grab whatever. Works well for pulling out hair. Might be worth a try to see if something is down in there somewhere blocking the water from the holding tank.

09-22-2021, 01:24 PM

There is no "P trap" or "S trap" on an RV shower. The drain uses a HEPVO valve to prevent backflow. If you put a snake through the drain, you'll destroy the HEPVO valve rubber bladder and will need to replace the entire HEPVO valve to prevent sewer odors from entering the shower drain and smelling up your bathroom.....

09-22-2021, 01:28 PM
probably better not use the device I described either. That is one of the great things about this forum. people are always trying to look out for each other!!

09-22-2021, 01:44 PM
There are several threads on this forum that discuss HEPVO valves and how they work. This link is to one that's used on an outdoor kitchen sink, but the valve is identical to the one used in RV showers.


Take a look at the drawings in post #19 and you'll see why "running a snake through the drain" isn't such a great idea.... Pull the rubber insert out or rip it and the entire system is shot. Also, if you remove it, make sure it's inserted "ribs down" or you'll be taking it apart again after a week of use.

travelin texans
09-22-2021, 01:58 PM
Sounds like you may have a 3rd grey tank with the drain handle hidden as several have posted. Everything's draining normally but the tank is full, regardless of what the sensors are reading.
Look closely underneath around the axles.

09-22-2021, 02:30 PM
The specs on that trailer show 30 gal of black tank and 60 gray. My guess is you have two gray tanks. Start looking for the third handle or signs of where it may have been if it fell off.

09-22-2021, 02:32 PM
OP how MANY drain handles have you found and pulled? Forget In Command and any readings for the time being - have ALL tanks been drained? If your sink is backing up into the shower neither the sink nor the shower is stopped up at the "trap". Sounds like you have a full gray tank you haven't drained.

You have 1 black tank and 2 gray tanks, have you pulled ALL 3 handles and let ALL the tanks drain?

09-23-2021, 01:22 PM
knife valve actually opening? see if the metal rod still screwed into the knife

09-23-2021, 02:46 PM
MY GOD MAN ! ..PUT THE TOOLS DOWN FOR A MOMENT!…BACK AWAY SLOWLY!!! :popcorn: lol …the suspense is killing me …it’s like yelling at the movie screen in a horror movie …lots of good info on here….I had no idea about the special shower drain valve. I do all my own plumbing from boilers to vacuum toilet systems in my boats…never heard of this one..thanks

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