Easiest access to the black tank flush connection

[zeus7625]

2012 NT 21FBS
We love it!
After our first camping excursion in our new camper last year I noticed a leak when dumping the grey and black water tanks. A trip to the dealer and it was repaired by replacing the common line between the valves. I won't go into the details about time and parts availabilty.

After our second camping excursion, the leak re-appreared. A trip to the dealer and it was repaired by replacing the last section of drain line to the flexible hose (bad joint glue). Once again I won't go into the details of time and parts. I was assured by the dealer that everything was filled with water and checked for leaks. Nothing leaks from the commode or sinks to the flexible hose connection.

After our third camping excursion, another leak coming from further up the drain line. This time I carefully dumped and watched what was leaking. The leak only happens when I'm dumping the black tank and flushing at the same time. It's clear and not black water. I can only assume it's the connection at the black water tank for the flushing water or the back side of the rear wall connection and running down the piping.

Has anyone experienced and repaired this problem?
Before I remove the bottom cover to the trailer, is there an easier way to the connection? Remove the commode?

thanks in advance for help and ideas.

Jesus

 

[cookie]

I am not familiar with the NT plumbing, but there should be an anti-syphon valve in line with the tank flusher.
These have been known to leak at either the valve itself or the connections to it.
Like I said, I don't know where it is located in your NT so you will have to look around. It is most likely up in a wall somewhere, as it has to be higher than any water source in the camper.
You might want to call Heartland Customer Service for it's location if someone here on the forum does not come up with an answer for you.

Peace
Dave

 

[Ray LeTourneau]

Jeses, The nest time you use the tank flusher, listen carefully for a light buzzing or vibrating sound. This is the anti back flush valve Dave is talking about. If you can gain access to it, you may find the leak. Otherwise, you'll have to dig deeper or it's back to the dealer with your theory. I bet you're right though. It sounds as if it could be from the flusher line. I don't know how they are attached to the tank though.

 

[JohnDar]

Looking at a floorplan for your rig, I'd hazard a guess that the anti-siphon valve is located behind the corner of your shower enclosure. If there's a white "disc" under the shower faucet, remove it and have a look. This photo is from a BC under construction, but it should give you an idea of what you're looking for. The valve is the small black object attached to the blue PEX line.

View attachment 20414

 

[zeus7625]

Final resolution
I removed the belly cover at the back end of the unit and was able to find the pvc piping to the flush connection and evidence that it was leaking from upstream. I removed the three screws that holds the connection to the back of the rig and pulled it out slightly (whatever the slack in the piping would allow) and connected a hose. As soon as I turned on the water I could see the leak where the piping threads into the connection. One call to the dealer and I have a brass replacement for the plastic valve assembly. The dealer stated that the plastic valves are known to leak and he sells a lot of the brass replacements. Reconnected, no leaks. Reinstalled, no leaks.

Thanks for all the help and advice.

 

[donr827]

Nice job Zeus. Thanks for posting your fix.
Don

 

[RCF]

Did you replace the part that a water hose connects to on the trailer? Or the anti-siphon valve?

 

[zeus7625]

Yes. It was a complet unit. The exterior female hose connection and the interior anti-siphon valve that connects to the internal piping adapter.