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!

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!

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 ....

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.

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.

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.

Black water tank not draining completely | Good Sam Community

MeloyeloCJ7
Explorer
Aug 09, 2013
Got a call from the dealership saying it was all finished up and ready to go. I went over yesterday afternoon to pick it up. Service manager said they put the brace in under the tank to bring the belly up flat. He said that on this particular tank the drain is located at center rear, so he went ahead and tilted it downward a little more to aid in compete draining. He also said that the elbow connected at the exit of the tank was tilted up slightly thus not helping the entire situation. He went ahead and redid that to bring it down into line. I looked down into the tank through the toilet when I got it home and everything looks all nice and clean in there. Hopefully this will bring this little situation to a close. Going to James Island in Charleston, SC end of this month, so I guess we'll see.
93Cobra2771
Explorer
Aug 05, 2013
Yikes! Thanks for the followup!
paulcardoza
Explorer
Aug 05, 2013
Wow.... Scary that this would happen so quickly in a new rig! More of a poor design issue than a component failure. I would insist on the brace, whether or not they replace the tank. That should prevent it from happening again.

MeloyeloCJ7 wrote:
Ended up taking the TT in to the dealer a couple of weeks ago for evaluation of the black tank issue. Hadn't heard anything from them, so I went by there this past Saturday to see if they had gotten around to checking it out. I talked to the shop manager and he said they couldn't find any kind of clog, so they had removed the underbelly to take a look at the tank. What they discovered is that the tank is sagging in the middle. He actually walked me back in the shop to show me the situation. Sure enough it looks like the tank was drooping down about 3 inches from where it should be to allow it to drain correctly. He said they had already talked to Forest River warranty about it. They are going to try to put a brace across the frame and against the bottom of the tank to bring it up to where it should be. If that won't work, they are going to replace the tank. I'll post again once it's all said and done with the final result.
MeloyeloCJ7
Explorer
Aug 05, 2013
Ended up taking the TT in to the dealer a couple of weeks ago for evaluation of the black tank issue. Hadn't heard anything from them, so I went by there this past Saturday to see if they had gotten around to checking it out. I talked to the shop manager and he said they couldn't find any kind of clog, so they had removed the underbelly to take a look at the tank. What they discovered is that the tank is sagging in the middle. He actually walked me back in the shop to show me the situation. Sure enough it looks like the tank was drooping down about 3 inches from where it should be to allow it to drain correctly. He said they had already talked to Forest River warranty about it. They are going to try to put a brace across the frame and against the bottom of the tank to bring it up to where it should be. If that won't work, they are going to replace the tank. I'll post again once it's all said and done with the final result.
MeloyeloCJ7
Explorer
Jul 19, 2013
Nope, definitely not new to this. This is our third TT and I've never had an issue like this with black tank. I know all the rules for good maintenance and until now have never had a problem. I'll most likely be taking it on to the dealer for a look see. For sure don't want things to get worse. Thanks.
ksg5000
Explorer
Jul 18, 2013
This doesn't appear to be your first RV so std maintenance of black water tank shouldn't be anything new to you - somethings not right and your rigs new and covered by warranty - drain the tank as best you can and take to the dealer and get it fixed.
MeloyeloCJ7
Explorer
Jul 18, 2013
Went ahead and did a fill and dump of the black tank several times using the built in tank washer. I feel like I'm in better shape now, but still not sure if it's all good. After the last dump I stuck a short section of PVC pipe down the toilet to see how deep the remaining water was. It was only about 1/2" deep best I could tell. I put in a few gallons of water and treatment to start again. All I can do is keep an eye on it the rest of this trip and go from there. Thanks again for all the input.
RJsfishin
Explorer
Jul 17, 2013
If you take it to the dealer, you had better hope it is the fault of the MFG, and not fault of not using enuff water, or not letting the tank fill completely before dumping. If it is your fault, you will not only pay, you will pay dearly !
skipnchar
Explorer
Jul 16, 2013
I SUSPECT others have identified your problem but you MAY have an increased problem now by the use. If the previous dumping allowed only the liquid to drain (likely if it's a cut out obstruction) then the solids are now built up behind the blank that was originally closing off the tank. Get it back to the dealer and let him fuss with it because it may be an UNSANITARY job to get the blank removed with a clog behind it. REMEMBER too that in order to assure no OTHER clogs, NEVER leave the black tank dry (you did well on that) and NEVER dump a tank that is not close to full and ALWAYS use lots of water when flushing.
Good luck / Skip
lanerd
Explorer II
Jul 16, 2013
THIS is the flush king. The advantage to this item is that you can connect your rinse hose to it and push water back up the drain pipe into your black tank. Normally, the opening (connection) between the tank and drain pipe will clog with tp or other waste and not allow the tank to drain. The flush king will force this obstruction back into the tank.

Your built in rinse feature allows you to put water back into your tank also, but does not go through the tank/pipe connection. It typically will have a sprayer inside the tank and it will help to clean the inside of the tank.

Walmart sells a device much like the flush king but does not have the attached gate valve to it. However, it too will force water back up into the tank via the tank/pipe connection and will serve the same purpose as a flush king. About half the price.

Hope this helps

ron