Forum Discussion

CarArt's avatar
CarArt
Explorer II
Sep 06, 2018

Gray tank plugged, limited options

Yes, I know it's been beaten to death but please bare with me.
70, disabled, on SS so on a budget. Not the issue, just sayin'. Yes, I'd love to have Joes RV Specialist come out but I need to try something on my own first.

My gray tank will not drain, says full, believe it since if I add water to kitchen sink it leaks onto the ground(?) from beneath RV(covered underbody so I can't see from where). I've endlessly searched the options but it seems with a full tank, not being able to move my RV out of the parking space, this creates some issues. Tried a snake, down the vent tube too. Not sure it gets where it needs to be because of turns in the plumbing. Thinking it's simply partially full of sludge since the valve seems to operate ok and I've replace the black one myself so I know what goes wrong. I'm fairly careful about what I let go down the sink but we all know sooner or later likely to have an issue. I have screens in my kitchen sink but I bought it used so...?

To the meat of my question-
I'm considering trying a variation on something I've seen but that I haven't really seen anything about specifically. And I've looked. Attaching a garden hose to the Clear 45 Degree Hose Adapter Sewer Fitting(Main), closing 2 valves on black and bathroom gray tanks, then opening garden hose attached to the adapter and letting water pressure go up to the blocked kitchen gray tank(this valve open) and "backwash" the plug, shut off then hopefully it will break free and flow out. Probably repeat.

Obvious issues-

1. too much water backwashing and shooting up and out kitchen sink/plumbing not intended to contain pressure. yuk. Plan to just open the garden hose, watch as it fills the Clear 45 Degree Hose Adapter Sewer Fitting, shut off- see if I get the release coming back out.
2. worried about breaking plumbing/tank but again will not just open garden hose and let it run. Open/close and look for release.

anyone try this? have any "no way!", "watch out for this", "glad we're not neighbors" "Genius!"
  • dougrainer's avatar
    dougrainer
    Nomad
    Sep 07, 2018
    There is no rule that states the 1.5 inch vent pipe has to go straight up from the tank to the roof. Even if there is a Y in the wall, you can probably snake a tube down to pump it out. IF you have 2 tanks and 2 roof vents, then no Y. IF you have 3 tanks and 3 vents no Y. BUT, they may have a slight ABS elbow going up, but that would still allow a snake hose to go into the tank. What I do when I suspect or verify a Valve has broken loose from the handle rod. I drill a 1/4 inch hole thru the center of the valve 180 degrees opposite of the original handle and then run a 1/4 steel rod into that hole and push the knife valve open. The 1/4 inch steel rod minimizes any leakage. You leave it partially in the drilled hole to seal, until the tank is empty. Then you have a empty tank when you replace the valve. Not sure if you stated, do you have a mechanical manual HANDLE or you have the Cable driven Dump Valve? If cable driven you can usually access the pull rod where the cable attaches at the valve and pull it open. Doug
  • CarArt's avatar
    CarArt
    Explorer II
    Sep 07, 2018
    thanks dougrainer. 3 tanks, 3 vents. Going to see whats up down there. I replaced the black tank valve and remembered doing something similar. Good info, thanks again. Lived in Carrolton myself.
  • down_home's avatar
    down_home
    Explorer II
    Sep 08, 2018
    Cal the factory. They made it with the two tanks exiting in one opening.
    Ours is the same way. If black tank the toilet goes straight down into the tank.
    The gray tank...its either the valve or a piece of something. Drains have screens so it is unlikely someone dropped something down it.
    If you dump grease down the drain, over a long time you may have a lump of it blocking things up.
    I'm not familiar with removing the drain valve but last resort you may have to.
    If you can establish that the drain vale is open a snake may be inserted through that way and break things up. Just be careful not to damage valve
    Leak? If you have a large puddle, on the ground, then there is the reason nothing is coming out the drain. It's liquid part, at least is, already out....unless you overfilled and gray water came up through the shower and out, or out the vent and ran down the side of the RV.
  • Garciawaters's avatar
    Garciawaters
    Explorer
    Sep 17, 2018
    Hello fellow RV'ers. First time utilizing Sony type of forum. I recently had the same issue. My galley grey tank was clogged with calcium, grease, food ect... after cutting the pipe under the tank and placing a double fitting problem solved. I am however, having a issue that continues to occur after that four order of a clog has been resolved. I had the carpet and padding pulled out and vinyl planking put in. I have a sludge like substance seeping up through the cracks in the planks. It hardens like tar and is so foul smelling. I clean it and it returns. This is actually how I discovered that I had a clog in the galley grey tank in the first place. After the clog was removed and the smell under my rid subsided, I am left with this sludge. I am very hesitant in removing the flooring to expose the wood underneath. Does anyone have any suggestions as to what to do. Or even what ot is. My fear is that the clog was there for years and it seeped through the wood floor causing mold and just plain garbage water to soak the wood. I should say I'm a first time rv owner and live in my fifthwheel year round. Also I'm a 48 year old woman who has fixed everything that has occurred myself. This one though seems a bit daunting. Help?????
  • theczar's avatar
    theczar
    Explorer
    Sep 18, 2018
    Seems like all the suggestions will result in a significant mess which the campground, you or your neighbors will not appreciate. I had a problem similar to yours only it was the black tank. Ugh! After thinking about it I came up with a device to use water pressure to clear the clog while still keeping the sewer connection hooked up. I decided on getting a clear sewer elbow, some pex, a hose connector and grommet. I drilled a hole in the elbow. Hooked up the pex to the hose adapter. Put the grommet in the drilled hole and inserted the pex.

    Hooked up the device, connected the sewer hose to the end of this to the sewer hookup. Put a hose on the connector and you are ready to go. You can push the pex in or pull out through the grommet to fish the pex into the correct branch of the system. The pex being 3/8 inch restricted the flow so the water was like a jet and it broke up the blockage and all flowed through the system to the sewer with barely a drop of liquid spilled. Pressure will not build up in the system since water is allowed to drain

    I will try to get you a picture when I’ get to the storage lot. Here are a couple links to some of the parts referenced above

    https://www.walmart.com/ip/Camco-Rhinoflex-Swivels-90-Clear-Fitting-Odortight-Connection/23636867

    https://www.homedepot.com/p/SharkBite-1-4-in-3-8-in-O-D-Brass-Push-to-Connect-x-3-4-in-Brass-Garden-Hose-Thread-90-Degree-Dishwasher-Elbow-U2276LFA/202721837

    Good luck
  • cephoto's avatar
    cephoto
    Explorer
    Sep 18, 2018
    Exactly. Well not exactly but something very similar in mind. Using the clear elbow. But after listening to the responses and then doing a lot more research I’m thinking it may be as they’ve said above that it’s the valve. I went to YouTube and found very technical information from valve manufacturers that seem to describe my issue.
    Since you’ve been kind enough to provide your thoughts, maybe I’ll pick your mind just a little further.
    Solution # 2
    As you say no solutions, especially replacing the valve with a full tank could spell disaster. So at this point I’m sure that I have to figure out a way to drain the tank in place, without spills before attempting the valve replacement. Problem.
    Inside my RV I know where the tank vent comes up through the wall and I think I can easily gain access to it. I was thinking of cutting through the pipe several feet above the floor and then renting a pump, dropping the intake hose down into the full gray tank, the outlet hose into my toilet with the black tank valve open.
    Opinion(s)?

    Thanks regardless.

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