Slow draining grey tanks

[Magnolia Tom]

So I went camping last weekend and when I was breaking camp and draining the tanks, I noticed both grey tanks didn't drain as quickly as they once did. Should I be looking at the vent or possibly the check valve? I don't think both would have a cutout blocking the line at the same time. Suggestions? Should I get on the roof with a water hose in the vent stack to clear it out? Seems to me there could really only be two possible causes....bad valve not opening all the way (which I think is unlikely since they are both doing it) or bad venting. Any help is appreciated.


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[abarkl]

We have noticed the same thing with our Jayco but not previous RVs. We checked and tried all the usual things as you mentioned but nothing changed.
From another member's observation we also noticed our final drain pipe was tilted slightly upwards.
We accepted it and moved on.

[Magnolia Tom]

If it were slow from the time I got it, I would just accept it as "normal". But since this is a new occurrence I want (need) to find the problem


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[Bookemdanno]

Off the top of my head, was the site level if dumping at the site? I had that happen last summer at a site, but I thought it was because the front had to be WAY nose down to be level on the site. I haven't had the problem reoccur.

[TaftCoach]

Or maybe this is normal and the other was abnormally fast ;-)

My next attempt would be to fill it to full and see what happens. Mine have always started fast and slowed as they neared empty. If there is a blockage extra flow from a larger volume of water may help.

Inspection cameras are pretty cheap now that might also be fun to shove up the pipe.

[troutslayer]

I had a piece of "debris" in one of my gray tanks when it was new. It was a plastic disc a little larger than the size of a quarter. I use the Sewer Solution so it got caught in the clear plastic viewing port. Someone mentioned an inspection camera...that may be a good place to start.

[Magnolia Tom]

Originally Posted by Bookemdanno

Off the top of my head, was the site level if dumping at the site? I had that happen last summer at a site, but I thought it was because the front had to be WAY nose down to be level on the site. I haven't had the problem reoccur.

Site was level, rig was level.


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[Magnolia Tom]

Originally Posted by TaftCoach

Or maybe this is normal and the other was abnormally fast ;-)

My next attempt would be to fill it to full and see what happens. Mine have always started fast and slowed as they neared empty. If there is a blockage extra flow from a larger volume of water may help.

Inspection cameras are pretty cheap now that might also be fun to shove up the pipe.

I was at a full hook up site, so I refilled to "flush" the galley tank and same thing.


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[TaftCoach]

Inspection cameras are under $20 on Amazon. That would be my next step.

[Magnolia Tom]

Think you're right Coach. Getting my plumber buddy to come over with his camera to investigate


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[Brownie]

I had that happen about 9 months ago (after full-timing for over 1-1/2 years). I dumped some Borax and water down the shower drain and let it sit for about a day, then dumped it. Low-and-behold, out came a huge clump of dog hair (from bathing my dog in the shower). Did the same for the kitchen grey, and now they both run fine. You might try that, or even some Draino.

[Magnolia Tom]

Thanks for the suggestion Brownie. I'll give it a try. Can't hurt [emoji3]


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