I've almost survived the first Massachusetts winter in my 2005 25' International CCD. I'm hooked up to a septic system, but my black water tank is no longer draining properly. It only drains very slowly and has backed up all the way into the toilet. My gray water tank is draining fine. My guess is that either the black water tank itself or its outflow pipe is blocked up. I've tried the mild enzyme-based septic tank treatments without success. My only thought is to try something more serious, Drano or the like, but the Airstream manual has made me paranoid about using something so corrosive in the system. Should I not worry about this? Is there something else I can try?
I'm definitely not an expert, but have you thought of hooking up and taking it for a drive? That sloshes things about and beats up the paper products a bit. Speaking of which, do you use RV single ply paper? I admit we use Cottonelle single ply paper because I'm cheap (RV paper is pricey in my opinion) but it has plugged up the toilet once already. RV single ply is much thinner and breaks up faster. I noticed our Target has it in our camping section. We may switch to that.
Mrs. RedSHED
Do you let the black tank fill before draining it, or are you leaving the drain valve open all the time?
Matthew,
I have cleared 'more that one' black tank clog. Some are easy, most are difficult to impossible. It's important to know if you have been leaving the black tank valve open while connected or not.
It it HAS been open, then you have what's known as the 'black hills' residing in your tank. This is caused by insufficient water from each flush letting the liquids drain and the solids remain.
The accepted technique is to let the tank fill and then drain it in it's entirety, flushing it 1 or 2 times after that.
If you do indeed have Black Hills Syndrome, the only way I have found to clear this is to fill the tank with water, call a local septic service that has experience with RVs AND HAVE THE TANK PUMPED!
This is the only method I have used that works every time.
__________________ Lew Farber -Certified Master RV Tech (currently on Forums sabbatical) WBCCI #1456/VAC (assoc) #1456 AIR # 10325 CHARTER MEMBER: FOUR CORNERS UNIT
Wow! Thanks for all the speedy replies. Here are the answers to your questions.
Have people had good luck with a snake? I really don't have a good sense of how the plumbing is laid out. In my imagination, there's a pipe from the toilet, a big tank, and then a pipe out. It seems like it would be tough to get to the outflow pipe from the inside, if that is where the blockage is, but a snake would work if the blockage is "upstream". I'm a bit worried about snaking from the outside and releasing the 18 gallons because I don't know how fast I can get the sewerage pipe back on. Still, snaking from the inside would be an easy experiment. I'll definitely try it.
I think a drive is a great idea to "shake things up" in there, but the winterizing I needed to do on the pipes makes this a hassle and I was hoping to make it to the spring thaw without moving.
I've been using regular paper, but I'm switching to something more Airstream-friendly after this experience. Thanks for the tip about the single ply paper.
I leave the tank open all the time. This has worked fine except for in the coldest of winter, about two months ago, when it froze up and I had to hook up a heat cable to fix it. I may have Black Hills Syndrome. The tank is draining very slowly, so it would take some time (weeks?) for it to empty. I think this rules out the drain-and-fill trick. I may indeed have to call a septic service for this, but would love some other ideas to try first. I wish I could see what's going on in there.
Is the garden hose technique sounds promising. Is it just being used as a snake, or is the water flow critical? I really can't get any more fluid in there without creating a serious mess.
This may sound a little defeatist, but FWIW, you're wasting your time trying to undo the 'Black Hills'. I have tried and discarded just about every technique, gadget and rumor out there to try to clear black tank blockages caused by an open black tank valve.
You are sure welcome to try them, but if you really want to save your time and ultimately your $$$$$.........CALL THE SEPTIC SERVICE!!
The huge power of the vacuums on those trucks is the only thing that will get you cleaned out. And BTW, have them do it 2 or 3 times with you filling the tank with water each time. IT WORKS!
__________________ Lew Farber -Certified Master RV Tech (currently on Forums sabbatical) WBCCI #1456/VAC (assoc) #1456 AIR # 10325 CHARTER MEMBER: FOUR CORNERS UNIT
2airishuman, I followed your instructions. No luck from above, no matter how much I thrashed the hose around. I don't think the drain is directly below the toilet in my tank. I poked around the bottom with a headless plunger and couldn't feel the outflow pipe. Anyway, I took the hose outside and removed my sewer hookup. The black water pipe drops vertically out of the bottom of the Airstream, turns 90 degrees to the horizontal, and then runs about two feet before it connects to the grey water pipe and the the sewer hookup. I could push the hose up the pipe only about a foot and a half before running into the blockage. After about 10 minutes of poking, I felt it begin to move. I quickly withdrew the hose and there was a moment of panic when it snagged and I realized I couldn't close the valve with it in the way. Fortunately, the 18 gallons of black water was held back for a few more critical seconds and I was able to get the hose out and the valve closed. After re-attaching the sewer pipe, I opened the valve and the tank drained successfully! I flushed it a few more times and everything seems to be operational again.
Thanks again to 2airishuman and everyone else for their replies!
Be prepared to get dirty.
Close the black water drain valve.
Pour three 5 gallon buckets of water into the black tank.
Let it sit for several hours.
take the slinky hose loose from the ground drain, leaving it attached to the trailer.
Pull the opening up about waist high.
While holding it at that level, have someone pour a couple to 3 gallons of water into the slinky hose.
Stuff the end of the hose with plastic Walmart bags.
Now, this is the trick- I will try my best to describe it.
Hold the hose down close to the ground , and then raise it as high as possible, as quickly as possible, holding the hose only at the end next to the ground drain connector. This will cause the 2 to 3 gallons of water to go rushing back into the black water tank with the pressure of about 18 lbs rushing against what is most likely clogged up paper in the black PVC piping.
You may need to do this a number of times. I would do that motion at least a dozen times, before remmoving the bag plug, and trying to see if the tank will indeed drain.
This will work except in the most seriously packed cases. Sometimes, it takes 2 dozen sloshes (back and forth water action against the clog) to break it loose, however, it works. Believe me, from experience, I can say it works.
Credit for this solution goes to the late Dick Norsworthy and the ever present Ben Millard, both WBCCI members in the GA unit.
Good luck.
If you have questions, give me a call
Best of all- its FREE!!!!!!.
Jerry 404-376-5937
__________________ steelbird312 2000 390 Landyacht XL 1989 29' Excella
WBCCI #6673 jerry Hodge
Have no intention of arriving at the grave safely, but rather to skid in sideways, chocolate in one hand,throttle in the other, totally worn out and screaming "WOO HOO, WHAT A RIDE!"
Now, after the spring thaw and you hit the road again, drain your tank as well as possible, add a couple gallons of cold water and a couple bags of ice cubes from the store. Drive over something else than smooth freeway for a few miles (until the ice melts) then drain and flush with clean water. Should break up any remnants left over from the clog. Darol
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