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Steve F.
Steve F., RVIA Certification
Category: RV
Satisfied Customers: 443
Experience:  Journeyman and Master RV technician, Mechanical & Aerospace Engineer. RVIA Technical Consultant
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1994 Alpha 5th Wheel. Our 50 gal. Black Water tank is clogged.

Customer Question

We have a 1994 Alpha 5th Wheel. Our 50 gal. Black Water tank is clogged. How do we clear it? We are living in it at the moment.
Submitted: 6 years ago.
Category: RV
Expert:  Steve F. replied 6 years ago.



Are you saying that the tank won't drain, or the toilet drain is clogged?



Customer: replied 6 years ago.
I'm saying the tank is full. We are putting Thetford Tissue Digester in it. We had to turn off the water because it came up through the drain pipe. Are there any RV Plumbers who have the equipment to deal with this type of situation?
Expert:  Steve F. replied 6 years ago.

That's a good start, RV shops would probably first try a tank flushing wand, followed by a toilet snake. After that, we would start to disassemble things.


So, the tank is full, and opening the waste valve won't allow it to drain because it's clogged down there, correct?

Customer: replied 6 years ago.
Well, as it went, we found someone through Rotorooter who comes out to evacuate black water tanks. Our 5th Wheel was connected to directly to the septic of the mobilehome park. He first took a flexible hose and ran it down our toilet. Seems our toilet has a 90 degree angle, and he could go just so far. Then he went outside undid a rubber seal, sawed something off an ABS pipe and inserted it into teh rubber seal, closed all vents except to the toilet and let it rip. He was able to get a lot out, but he said he didn't get all of it out. So, now we have the tissue digester in there and will fill use the water unspareingly and see how it turns out. We have been living in our 5th Wheel for about a year and this is the first incident like this we've had. So, needless to say, things are fixed. Thanks for your assistance.
Expert:  Steve F. replied 6 years ago.

It was my pleasure. If you feel I have helped you at all with this problem, please consider clicking on "Accept" so I can be paid for my time assisting you.

Please come back again and ask for me in the future if you need help with a coach problem.

Customer: replied 6 years ago.

A wand cannot be used in the black water tank on our year and model of 5th Wheel. I had called around for someone who could vacuum the tank on a Saturday. This was done before I received your answer and without disassembling anything. Thanks for your input.

Expert:  Steve F. replied 6 years ago.

You are welcome.


For future reference, another expert reminded me that Happy Camper makes something called "Extreme Cleaner" which is a very good tissue digester. It works in about 3 hours.


You may also want to add a valve by Valterra, and when combined with their HydraFlush lets you connect a hose directly to the tank to really get a good clean that can be viewed through plexi-glass. I had forgotten about these but have used them to good success.


About $50 for the whole set up. Happy Camper is in Medford, Oregon