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MeloyeloCJ7's avatar
MeloyeloCJ7
Explorer
Jul 16, 2013

Black water tank not draining completely

New TT is a 2013 Forest River Surveyor SV301. It has a 30 gallon black tank. First trip was only for a couple of nights to check things out. Appeared that everything worked as it should and was very pleased. We are now into our second week of our yearly trip to OBX and it looks like we have an issue with the black water tank. After only being here for about 2 days I checked the monitor and it showed that it was full. I thought OK ???, and went ahead and drained the tank, put in a couple of gallons of water along with the water treatment. Since I was used to getting almost a week with our previous TT (40 gallon tank) I thought this didn't seem correct and started to keep an eye on it. After about 1 1/2 days it was showing full again. I thought no way. I got out my flashlight and looked down in the toilet. Sure enough it was FULL. I opened the drain again and got the big swoosh of water as usual. I even let it go for awhile just to see if it might be a slow drainer. After about 10 minutes I looked back down into the toilet only to see lots of water still in the tank. Obviously it's not draining all the way empty for some reason. I'm now needing to drain it every couple of days so we can still use the toilet. Just looking for some advice here on what I might be able to try before having to drag it in to let the dealer take a look. Thanks!
  • Already tried to backflush with the outside connection. Didn't appear to make any difference. I just dumped the tank again because it was way full. When I look down into the toilet, there is still waste and water in there for sure. Is a Flush King basically the same thing that comes built into campers? Thanks for the input.
  • Since it's new just bring it back to the dealer - sounds like the plumbing is botched up and chances are it will be a stinky/messy fix.
  • Not familiar with the model. If you are able to back flush from outside, give it a try then see if you get the whooshing sound and then trickle down. If so, safe to assume you may have some pieces in the tank acting like a flapper. Unfortunately that could very well mean a trip back but hey, that's what a warranty is for.
  • Sounds like an obstruction, sometimes when they cut the vent and drain holes they leave the plug in the tank (foolishly) and it lodges when you drain....Drain it again look down the bowl with a flashlight, send a hose in from the discharge end, just start looking.....also check your vent on the roof, make sure it is clear, flush the tank if you have a connection. One last thing, ignore the sensor, they never work correctly ....
  • Possibly a cutout that's getting pushed toward the exit pipe. You might be able to get it with a combination of backflush from the outside and wet vac with long hose from the inside. Won't be pretty!