VERY slow shower

[casey]

I'm assuming this is "just" a shower problem since I haven't had a problem with the sink that I know of.
The shower is really really slow to the point where the pan will fill up even with a "Navy" shower where the water is not even on most of the time. The water drains very slowly. I can run a snake down five feet. We had trouble running a snake from the other end and had to use force to apparently shove something out of the way. When the trailer was new, upon the first black water draining a LARGE piece of aluminum presented itself out the pipe and was removed by hand. The gray pipe is small enough that that size of aluminum would not be able to get out. Once we shoved whatever that was out of the way with the snake, the gray tank drained quickly but it did not affect the speed the shower drains.
I even went to the extent, out of desperation, of putting liquid plummer in the drain. It went down at the same speed as the water does, with no change in results.
So I am sort of at my wits' end trying to solve this. It "feels like" there is a gob of solidified something (hair etc) stuck in the drain pipe in such a way that the snake just goes around it. I"m considering getting can of compressed gas and trying that, lacking any other viable idea at this time. Or taking the tank off, which is going to be very difficult. I live in the trailer and can't just drop it off at a dealer to mess with for a week.
Ideas?

[charliem]

[font size="3"]You don't say, but I assume you still have the 16DB. If you drain the gray tank, allowing plenty of time to make sure it is completely empty, does the shower still drain slowly and the sink work fine? If so, I'm guessing the gas trap below the shower is defective. Some CLs, and probably the 16DB have a special trap, called a HepVo trap, below the shower to allow the shower basin to be low to the trailer floor. A standard P-trap requires several more inches of depth, thereby requiring a step up into the shower. This HepVo device is sort of a rubber tube that opens and closes with water pressure. It could have failed. If so, no liquid plumber, compressed air, or snake will fix it. The path from shower to gray tank is very short so the 5 foot snake was certainly well into the gray tank.

[a href="https://www.google.com/search?q=hepvo+1-1/2+waterless+trap&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ved=0CD4QsARqFQoTCMrp1NG7n8cCFYIFkgod498PKg&biw=1252&bih=543"]https://www.google.com/search?q=hepvo+1-1/2+waterless+trap&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ved=0CD4QsARqFQoTCMrp1NG7n8cCFYIFkgod498PKg&biw=1252&bih=543[/a]

[a href="http://www.amazon.com/Waterless-RV-Sink-Trap-1-1/dp/B00NLMPLDU"]http://www.amazon.com/Waterless-RV-Sink-Trap-1-1/dp/B00NLMPLDU[/a]

I'm not sure how to access this trap in your particular CL. It should be close to the shower drain, in line between the drain and the roof mounted vent pipe. It could be [/font][font size="3"]accessible through a side wall panel, or [/font][font size="3"]possibly be below the floor.
[/font]

[casey]

yes still have the 16DB. The gray tank is always run open, so yes the problem exists when it is empty. And the sink always drains fine. Your analysis makes perfect sense. So it sounds like I get underneath and look for some kind of tube that is blocked? I admit I don't understand how it would have failed, i.e., the mechanical explanation. Like, it is stuck closed perhaps, or nearly closed? Or is it possibly stuck open?

[tinkeringtechie]

[quote timestamp="1439239152" author="@ma" source="/post/14104/thread"]We had trouble running a snake from the other end and had to use force to apparently shove something out of the way. 
[/quote]LL uses a hepvo on the shower which acts like a one-way valve to prevent odors from rising up in the tank. Running a snake through it will probably damage it (especially backwards). It sounds like it already wasn't working very well though. Unlike a conventional P-trap it needs a little bit of water pressure before the membrane will open up (think like one of those party noise makers). Our shower has never been "fast", but it does drain completely. I'm guessing you need to swap out the hepvo or try to find an alternative. If you just need it to work you can bypass the hepvo with a tube, but you'll probably get some odors in the bathroom from your grey tank.

[tinkeringtechie]

yes still have the 16DB. The gray tank is always run open, so yes the problem exists when it is empty. And the sink always drains fine. Your analysis makes perfect sense. So it sounds like I get underneath and look for some kind of tube that is blocked? I admit I don't understand how it would have failed, i.e., the mechanical explanation. Like, it is stuck closed perhaps, or nearly closed? Or is it possibly stuck open?

Here are some graphics that might help show what the valve looks like:

http://www.hepvo.com/

[casey]

Thanks. It appears some crawling around underneath is going to have to occur. At least I have an idea what to look for now.

[tinkeringtechie]

[quote source="/post/14116/thread" timestamp="1439303155" author="@ma"]Thanks. It appears some crawling around underneath is going to have to occur. At least I have an idea what to look for now.[/quote]It won't be under the trailer... it's under the shower pan. You might have to remove trim/panelling to get to it.

[ttroup]

ma,

Did you find a solution?