Black Tank Flush issue

[chuckster57]

If it runs under the shower then I bet its in the wall behind the shower faucet. is the faucet mounted to a plastic square that is screwed into the shower surround? if so then you'll need to take it out. Been There Done That too many times to count.

[Prhodes]

Originally Posted by chuckster57

If it runs under the shower then I bet its in the wall behind the shower faucet. is the faucet mounted to a plastic square that is screwed into the shower surround? if so then you'll need to take it out. Been There Done That too many times to count.

Yes it is. 4 screws hold it on. I didn't want to get into that unless I had too. It's sealed with caulk. Looks like I will dig in later today.

[NH_Bulldog]

Mine had an issue with the rubber washer missing in the outside fitting causing water to spray outside when I connected the hose. The anti-siphon valve hums/buzzes when I use a restricted/low pressure water supply, but is quiet when I use a water supply with higher flow. When I use the system, water runs for a period of time in the tank before it starts to come out the drain. The angle/tilt of the camper also determines efficiency of the tank flush/flow. We have a rear bath so the tank drain is on the front edge of the tank., If the trailer is tilted to the rear even a little, it doesn’t fully drain and takes on a lot of water from the flush before appearing at the drain line.

[JRTJH]

Originally Posted by Prhodes

Thanks for the information! Valve not under sink. Red, blue only. No white. I can try to follow the white from the flush hook up and see if I can find it. It looks like it runs under the shower then somewhere else

Try to follow the line from the garden hose connection on the side of the trailer. That "should" give you some idea of where the line turns to go up. Where it turns is likely the spot where you'll find the valve (several feet above the turn). Often, if the valve is behind the shower wall, you will find a false back on a cupboard on the opposing wall. For instance, if the "common wall" is between the shower and the entertainment center, often there'll be an access panel screwed to the back of one of the entertainment center cupboards that's located on that "common wall".

One other "possible access" is by pulling the shower faucet and the standoff fixture it's mounted on. Behind that you'll find the hot/cold lines for the shower faucet and "SOMETIMES" (but not often) you'll find the anti-siphon valve and its plumbing lines sharing that space. I wouldn't start with this location because more and more, Keystone has stopped installing the valve behind the shower wall since it's a "often fail device" and access needs to be easy to get to for replacements....

I'd suggest you first try to trace that line from the outside connection. If it heads in the opposite direction of the shower, chances are you won't find the valve in the shower wall. So, "follow your nose" so to speak.....

[chuckster57]

I wish some of the other manufacturers would do the access panel, I always seem to cut my hand on the cut edges of the plastic and its a real pain to get the hose threaded if its pex line not flexible hose.

[JRTJH]

Originally Posted by chuckster57

I wish some of the other manufacturers would do the access panel, I always seem to cut my hand on the cut edges of the plastic and its a real pain to get the hose threaded if its pex line not flexible hose.

Yup, BTDT...

[mrbill4]

I believe Chuckster57 is exactly right that it's the valve. I just had the same problem with the 2009 Montana 3400RL we purchased two months ago. The repairman came to our site and replaced the valve. No problems after that. He told me the valve (one way valve) is usually located under the sink, but in our model it's located behind the shower controls. He said in our case it was because the trailer was not winterized correctly.

[Jim Aitken]

Are you sure you let the flush run long enough? The spray nozzle in the tank doesn't pass a high volume of water. On our Cougar it can be a couple of minutes before you see a flow coming out the drain and it is a relatively small trickle. If you are looking for a high volume flow you won't see it.

[rlogan11]

I had the same problem with our new 2019 cougar 30rls - black water flush water lines under the sink were reversed. Have dealer reverse the water lines and I think you problem will be solved

[BAPotter]

Try pressurizing the flush out line to 40 lbs or so. If it will pressurize, the valve is bad or reversed. If it wont pressurize the valve is open and working. (Be sure everything else is shut off.)

[travelin texans]

Originally Posted by rlogan11

I had the same problem with our new 2019 cougar 30rls - black water flush water lines under the sink were reversed. Have dealer reverse the water lines and I think you problem will be solved

Unless its deeply hidden impossible to reach turn it around yourself & forget waiting 6 months for the dealer to "get around to it". It's 2 fittings & most likely only hand tight. Be sure to mark the lines as usually they're both the same color so you don't repeat the backwards connection.

[chuckster57]

Originally Posted by travelin texans

Unless its deeply hidden impossible to reach turn it around yourself & forget waiting 6 months for the dealer to "get around to it". It's 2 fittings & most likely only hand tight. Be sure to mark the lines as usually they're both the same color so you don't repeat the backwards connection.

I have found that the IN line has a straight fitting and the OUT fitting has a 90 degree fitting, that way the valve can sit in the right (upright) position. Jayco jayflights came from the factory about 98% of the time with the valve installed sideways.

[Brantlaker]

Here is what I did in my Cougar and my Alfa Gold. I took it out and put a one way Foot Valve in the line going to the Black Tank and have a Hose Fitting back flow valve on my Hose both are Brass. The good thing is the parts cost less than the plastic one. Got it all at Lowes

[sourdough]

Don't see that the OP came back with a follow up on what was wrong. I guess we're assuming/hoping it was behind the shower controls??

[jimborokz]

Originally Posted by Prhodes

Thanks for the information! Valve not under sink. Red, blue only. No white. I can try to follow the white from the flush hook up and see if I can find it. It looks like it runs under the shower then somewhere else

On my other model I found the valve behind the convenience center. I was back there for other reason but noticed the anti siphon valve there. Also when it was brand new and I was running water to check all the water connections before I hit the road I discovered the black and grey dump valves were labeled backwards. I was trying to dump the black tank but was dumping the grey. I have seen this several times in threads so it is not uncommon. You said you had the back off the center looking for leaks. Take a good look for the valve there.

[rcashdollar]

Within the last week I also posted about problems I’ve had with my black tank flush on my 2014 unit that I purchased a couple of months ago. I did locate the anti syphon valve under my sink, removed it and it appears to be working correctly but still no flush. I went old school and used a wand to clean it and put the camper to bed for the winter. I plan on a looking into it in the spring and I even purchased a new anti syphon valve on Amazon that I’ll install. I’ve seen YouTube videos where the nozzle into the black tank (yuk) was plugged but with a new unit like yours I wouldn’t think that would be the problem. I’m fairly new to this web site and it’s awesome. Thanks

[jad59]

I added a check valve on the backside of the panel, mine seemed like it was allowing the water to siphon back out of the black tank really weird. My anti-siphon value is up the same hole as the shower water lines. If you do that you have to remember to blow the line clear for the winter.

[itat]

Originally Posted by jad59

I added a check valve on the backside of the panel, mine seemed like it was allowing the water to siphon back out of the black tank really weird. My anti-siphon value is up the same hole as the shower water lines. If you do that you have to remember to blow the line clear for the winter.

The valve is an anti-siphon/backflow preventer and vacuum breaker valve. It prevents liquid from being sucked out of the black tank in the event there is a negative pressure (vacuum) condition in the feeding hose. By code, it is installed at a level higher than the toilet rim. So, when you disconnect the hose from the inlet, the water in the hose between the inlet and the valve will flow downhill and back out the inlet because the vacuum breaker function in the valve that lets air into the line, but the water on the other side of the valve will not get back past the valve if the valve is working.

[Prhodes]

Sorry I haven't posted the results. Valve was located behind shower handles and YES it was installed backwards. I appreciate all the feedback guys.