Tank flush problem

[Newman252]

I have a 2016 Cougar 28RBS. On our first trip out in April I tried to use the tank flush. Nothing happened. It seemed as if the water was just stopping. I checked the vacuum breaker and found it installed backwards. Plus it wasn't working anyway. I tried to blow through it but it was seized shut. Instead of taking a 3 hr drive to take it in to the shop I replaced the vacuum break with a pex elbow so it would go straight through. Tried to flush again this weekend. Nothing. It acts like there is another valve or something stopping water flow. When I first checked the vacuum break one side did have pressure so I figured that's where the problem was. So now either I have a blockage after the vacuum breaker or I'm missing something. Is it just a straight connection with no valves? I really hate to make that 3 hr drive and lose my camper for the next month while it waits it's turn.


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[bill-e]

I have the same issue. I assumed that the output was blocked so I left the tank full of water overnight...didn't help. I'm beginning to think that like another owner, I have a kink on the line.

[malabarbob]

Same here on my 248RKS Bullet. First time out, no black drained. Took it to the dealer and he said he drained it and it was OK. Got it home, looked into toilet and saw wads of toilet paper (yes, we use RV stuff). Pulled it out with a grabber, added lots of chemical. Liquid seems to run thru OK. We have a 5 day trip coming up. Will try with just liquids and hope for the best.
Question - is what I see looking down into the toilet, the black tank or is that just a holding area until it reaches the height of the black pipe that then leads to the black tank?

[JRTJH]

The toilet dumps "directly into the black tank" in almost all travel trailers. In fifth wheels, there may, on some models, be an offset 3" or 4" black pipe leading from the toilet to the top of the black tank.

What you see, when looking down into the toilet on your trailer is the contents of the black tank. The toilet paper "wads" that you pulled out were "resting on the black tank floor".

The "key to success" with solids in a black tank is LOTS OF WATER. You need enough water (in the toilet bowl) to "flush the solids away from directly under the toilet" and when dumping, you need enough fluid to sweep the floor of the black tank clean (sunami action).

If I were you, I'd spend a considerable amount of time at a full hookup site or at a dumping station. Start by filling your black tank "brimming full" by flushing the toilet repeatedly. Once you are full, then go outside and pull the tank valve. Let it drain completely, then go inside and fill the tank again. Repeat this process until you don't see any "solid material" flowing into the campground sewer. Once empty, if you have any problems with your level gauges, you might consider an "enzyme digester" and another "full tank of clean water" to "sit and soak" for a few days.

After you're clean, you can "start fresh" with about 5 gallons of water in the black tank and remember that you need to "fill the bowl with adequate water" when you flush solid waste into the tank.

Think about the fact that most black tanks are only about 8" deep. If you "dump a solid mass" without adequate water to "splash it away", that mass will sit under the toilet "hole in the floor" and after several "solid dumps" you'll get that "pyramid of poo" that you described.

A good "old wive's saying" to follow is, "Dilution is the solution to pollution"....

more water, More Water, MORE WATER !!!!!

ADDED: Remember that any enzyme cleaner can only clean the parts of the tank on which it is exposed, so adding 5 gallons of water and a pack of "enzyme cleaner" and letting it sit will NOT clean the tank walls or top. The only parts of the tank that are exposed to the enzyme in that situation is the floor. So, if you want to clean your tank walls, the "black tank flush spray head" and the tank level sensors, you'll need to completely fill the black tank with water, add the enzyme packet and let it sit "COMPLETLEY FULL" for a period of time.

[ThePressureIsOn]

We also have a 248RKS, check out post #6. http://www.keystonerv.org/forums/showthread.php?t=22463

[bill-e]

We also have a 248RKS, check out post #6. http://www.keystonerv.org/forums/showthread.php?t=22463Different issue. We're talking about the fresh water tank flush nozzle being clogged in some way.

[14george]

Had the same problem took to dealer worked fine and still working. Think it was a kink in line

[bill-e]

I just looked inside the bottom, no kink, must be a clogged nozzle.

[SFGiantsFan925]

We have a new Bullet 272BHS with the hose connection on the outside. Our second trip I tried to use it. I connected the hose, turned it on, and it just sprayed water all over from the connection on the outside. I heard no water going into the tank, and it seemed as if the valve was stopping the water from going into the tank.

I had 2 people behind me waiting to dump so I just disconnected and used some water down the toilet into the tank to try and flush. So frustrating.

Why is it so hard for these things to work correctly?

Is there anything that needs to be done to get the valve to work? Or is it simply just connect a hose and turn on? There is a warning sign above the connection that says it could cause an "unsanitary" condition. I forget what it says exactly but it concerned me.

[chuckster57]

I've seen the vacuum breaker installed backwards quite a few times. Can't say kinked line is common, but plugged sprayer has happened a few times.

These things can and do work correctly when the dealer does a proper PDI. It never ceases to amaze me how many dealers will skimp on the PDI, and just "get 'em over the curb". We routinely see keystone products purchased from another dealer, that when we start warranty repairs it's obvious the PDI wasn't done correctly or at all.

Okay, I'm done. I'll get off my soapbox and watch TV.

[bsmith0404]

Listen closely to see if you can hear the water spraying inside the tank. Open the toilet and listen. I think many people believe the blank tank flush isn't working because they don't see water running out of the sewer hose. Not saying that is your case, but a possibility. Remember, the hose going in is 5/8", the amount of water it actually dumps into the tank is further reduced by the ability of the spray head. Your sewer hose is 3", you will only get a small trickle out of the hose. Personally, shut the black tank waste gate and let the tank fill up a bit to create a stronger out flow to help remove waste. Just don't forget about it and flood the bathroom.