36CKTS Black Tank Flush

DKRITTER · 08-06-2018, 02:54 PM

Last night we were packing up for an early trip home his morning.

I was back flushing the black tank and noticed some clear water coming out of the under belly. Shut it all off and I'll look at it in the morning.

Can someone possibly tell me where the backflush hooks to the black tank. Should I start in the basement or underbelly?

jetmarine5 · 08-06-2018, 07:47 PM

There's a check valve that is suppose to stop black water from contaminating city water. I had mine break on my Open Range. Had fresh water running on my bathroom floor. Valve was under sink on my model. Mtg. of valve gave me free replacement upon return of broke on. Cost new about $20.00.

florabama · 08-06-2018, 07:48 PM

I have a different model but the back-flush has a back flow or vacuum precentor which on my unit has leaked. The fresh water actually goes up, in my case under the bath sinks then cycles back down into the black tank.
Kinda hare to explain and someone else will fill in my blanks but this is a likely cause of the water leak.

DKRITTER · 08-08-2018, 08:44 AM

Well I was wrong! I crawled into the basement yesterday morning and followed the black tank flush line up into the bathroom (I never found the valve) but there was no water at all so I moved on.

Crawled under the trailer and took the plastic panels down and all the insulation was soaked. I found the flange for the black tank was broken and created a small leak.

So once again I have to take the valves apart. Probably going to do a major overhaul.

DavandJane1 · 08-08-2018, 02:16 PM

The backflow check valve is located under the medicine cabinet in your trailer. Had to change mine earlier this year so this is how I know.

Budman2082 · 06-28-2019, 08:51 PM

DavidandJane1 I have a faulty 571 valve causing black tank odor which is also under my medicine cabinet. Any pointers as to how to get to it for replacement? I only have a 4 inch opening in the side wall under my bathroom sink and can barely get one hand in there.

Thurman · 06-28-2019, 09:55 PM

@ "Budman2082": I had to change out the "Air Admittance Valve", which may be the 571, on a friends camper and it too was located up under the bath vanity in an area too small for my hands. Think as if you were building the RV. I found that removing the bath vanity was easy and allowed me easy access to the AAV.

Budman2082 · 06-29-2019, 08:50 AM

Thurman, thanks for response. Iam thinking your maybe right. Only concern is that plumbing is so cheaply made I won't be able to put things back together without something leaking.

aknavy · 06-29-2019, 10:49 PM

Quote:

Originally Posted by Budman2082

DavidandJane1 I have a faulty 571 valve causing black tank odor which is also under my medicine cabinet. Any pointers as to how to get to it for replacement? I only have a 4 inch opening in the side wall under my bathroom sink and can barely get one hand in there.

If it's like mine, there's a cabinet in the all above it. Take the four or so screws out, pull the cabinet out, and you have much easier access. Takes all of 15 min to pull the cabinet out, replace the valve, and put it back in.

Budman2082 · 06-30-2019, 08:00 AM

Believe it or not, my medicine cabinet is the only thing in the entire RV that is nailed in and not screwed like everything else.

Budman2082 · 07-02-2019, 05:25 PM

Well got the replacement 571 valve in the mail today. Took the plunge and went through the four inch opening. Couldn't see what I was doing everything was by touch, but evidentially I got the old valve off and the new one back on. The old valve was sticking in the open position which allowed black tank odor to escape into our bathroom. Once the new valve was in place the odor disappeared.
Thanks to all for your help and suggestions.

mlatter · 07-10-2019, 04:54 PM

Quote:

Originally Posted by aknavy

If it's like mine, there's a cabinet in the all above it. Take the four or so screws out, pull the cabinet out, and you have much easier access. Takes all of 15 min to pull the cabinet out, replace the valve, and put it back in.

I don't want to hijack the thread, but are you talking about the medicine cabinet in the bathroom that you had to remove to get to the air admittance valve? I have a smell as well, but I have never been able to find the valve.
Your trailer should be the same as mine.

Thanks!

aknavy · 07-10-2019, 05:17 PM

Quote:

Originally Posted by mlatter

I don't want to hijack the thread, but are you talking about the medicine cabinet in the bathroom that you had to remove to get to the air admittance valve? I have a smell as well, but I have never been able to find the valve.
Your trailer should be the same as mine.

Thanks!

Yes, the medicine cabinet to the left of the sink. There's an access hole under the sink for it, but I think you'd have to have multiple elbows in each arm to get the job done thru there!

I'm also paranoid about water leaks, and the only way to really see what is going on is to remove the cabinet - then you can see the valve, water lines, and floor.

BandJCarm · 07-10-2019, 05:27 PM

Quote:

Originally Posted by aknavy

Yes, the medicine cabinet to the left of the sink. There's an access hole under the sink for it, but I think you'd have to have multiple elbows in each arm to get the job done thru there!

I'm also paranoid about water leaks, and the only way to really see what is going on is to remove the cabinet - then you can see the valve, water lines, and floor.

Some magic way, I replaced mine through that opening/hole.

Turned out that wasn't the issue. The issue on mine was wrong plumbing where the black tank empties into the discharge tube. It looked like this (Before they totally replaced it):

aknavy · 07-10-2019, 05:29 PM

Quote:

Originally Posted by BandJCarm

Some magic way, I replaced mine through that opening/hole.

Turned out that wasn't the issue. The issue on mine was wrong plumbing where the black tank empties into the discharge tube. It looked like this (Before they totally replaced it):

That looks horrible. Like it broke and somebody decided to JB Weld it back together.

BandJCarm · 07-10-2019, 05:38 PM

Quote:

Originally Posted by aknavy

That looks horrible. Like it broke and somebody decided to JB Weld it back together.

It was the dealer. I don't go to dealers anymore.

It is some kind of butyl stuff. The problem was the discharge tube was not long enough for the adapter to go up inside the black tank, so it leaked....drip, drip, drip....till the insulation was soaked and fell out. Twice.

The fix was to rip it all out and start over with a long enough discharge tube to fit all the way inside the tank. No leaks (fingers crossed).

We lived 3 years with it. Took a while to get bad, but it was bad!

mlatter · 07-10-2019, 05:43 PM

Quote:

Originally Posted by aknavy

Yes, the medicine cabinet to the left of the sink. There's an access hole under the sink for it, but I think you'd have to have multiple elbows in each arm to get the job done thru there!

I'm also paranoid about water leaks, and the only way to really see what is going on is to remove the cabinet - then you can see the valve, water lines, and floor.

Awesome. I had plugged that hole under the cabinet previously as part of my mouse-proofing project. I'll pop out the cabinet and have a look.

mlatter · 07-10-2019, 05:46 PM

Quote:

Originally Posted by BandJCarm

It was the dealer. I don't go to dealers anymore.

It is some kind of butyl stuff. The problem was the discharge tube was not long enough for the adapter to go up inside the black tank, so it leaked....drip, drip, drip....till the insulation was soaked and fell out. Twice.

The fix was to rip it all out and start over with a long enough discharge tube to fit all the way inside the tank. No leaks (fingers crossed).

We lived 3 years with it. Took a while to get bad, but it was bad!

Wow. Keeping my fingers crossed that it's just my AAV that's the issue.

BandJCarm · 07-10-2019, 05:50 PM

Have seen a lot of CKTS CC's. None ever had this issue. I am sure you'll be ok. But you have to pull the belly pans to see if insulation is compromised. It's not that bad to do, or to put back. Just a drill and lying on your back.

Rich5117 · 07-13-2019, 02:56 PM

This is good time to ask. Had to remove my underbelly insulation for a lot of little different reasons, carpenter ants. Came up the sewer hose in one night had would say 200 hundred or so in insulation.

What exactly is the purpose of a 6 inch piece of batted insulation laid on the underbelly? It certainly is not providing any R value. I have not put any type of insulation back in as of yet.

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