Black Tank Flush

[AWF1945]

The flush doesn't work. Looks like it plumbed wrong unless I'm missing something. Blue pex goes from flush inlet up into coach up through floor, back down into black tank. ? Is there a check valve somewhere? If so, it may be installed backwards .. water does not flow at all..

Thanks

[fonzie]

Yes there should be a back flow preventer somewhere in the coach usually in the bathroom vanity...

[AWF1945]

Thanks for the quick response. . I did find it.. my guess is, the lines are reversed. Wonder does it have to be on that upward position to work..

Thanks for taking the time and send a picture.

[fonzie]

First I would tap it with the handle of a screwdriver to see if stuck and try black flush again. If not working then I would try reversing connections. On occasion people reported that the actual nozzle in the black tank was filled with construction debris (sawdust) thus preventing working properly.....good luck.

There are many threads on subject....

https://www.google.ca/search?q=black...rqHYaneqG8j5AM

[bclemens]

Yes...the check valve has to be above the flood line (aka above the toilet drain) per code.

[AWF1945]

I removed the check valve it appears to be free from debris. My guess is as suspected, the lines are backwards. I removed the line from the black tank itself and nothing.

Im shorthanded today. When I get it back home I'll have a partner bolw compressed air through the line with the valve removed and see whats going on.

The valve has to sit as shown in picture in order for it to function properly.

[rockfordroo]

Usually the inlet (from your hose) is at the bottom and the outlet (to your tank flush) is on the side. See pic on post #30 here:

http://www.irv2.com/forums/f112/tip-...-270158-3.html

They probably come up through the same hole and the guy could have easily got them mixed up when he put the valve on.

[dmax36]

Ive had the same issue with our DX3. To date I have not explored the issue.
Looking forward to your conclusion to help me troubleshoot ours. Please keep us posted......Bob

[bubbles]

I only post this as a reference for a typical black tank clean out system installed at the factory.

[AWF1945]

I will get to the bottom of it and let you know.. pretty straight forward I would think. Either the lines are reversed at check valve, or bad check valve. Kinda of a pain to get to, but could be worse. ;-)

[dmax36]

After a second thought, our Black flush is a separate input requiring a hose connection. This would be a entirely separate water system not in any way connected to the M.H.. I am curious if "Code" would sill require a Back Flow Preventor.

[Tommy Joann]

The back flow preventer is required to keep from fouling the campground water supply!

[AWF1945]

Its a simple system. See bubbles previous post with the picture. Yes, it's a separate line... mine is just not working should be a simple fix.

[bclemens]

Arrowd on the check valve are hard to read, but this it too common an issue. I had this at Sunseeker as well. I'll go check some online spot check direction. Then the valve itself. Maybe we're all just buying the same valve.

[bubbles]

This is what my Georgetown MH uses. As can be seen the input is from the bottom through the shut off disk controlled by pressure from outside connection and the top vacuum opening (vented to ambient) allowing input and closure of the disk when pressure is applied/removed. The output side connection (to black tank) is spring loaded to the closed position (toward main valve cavity) and opens when pressure is applied. I know this is not identical to the one in this issue but I believe the internal functioning is the same. Where this item is situated in the unit above floor level; for me 5 feet, well above the black tank, contamination of any sort is a moot issue.

[AWF1945]

Thanks for all the help gang. Problem identified. .. lines are reversed.

[dmax36]

Curosity got the best of me and I checked. Yep, ours is backwards also. For Brian's info, I don't know if the fitting installer is the same guy who run the lines, but the lines were crossed in the bay.
Can the fitting be simply rotated leaving the vent horozontal rather than on top ?

[rockfordroo]

Originally Posted by dmax36

Curosity got the best of me and I checked. Yep, ours is backwards also. For Brian's info, I don't know if the fitting installer is the same guy who run the lines, but the lines were crossed in the bay.
Can the fitting be simply rotated leaving the vent horozontal rather than on top ?

I wouldn't. I don't think it will work sideways.

[AWF1945]

It needs to be installed just as shown in picture. It has a ball, or similar that drops down and seals it off. Any other positions won't work.. I already check that possibility out..

[AWF1945]

Resolve, a trip to the local hardware. Sharkbite fittings, reverse the lines.. works like a champ. This way I didn't have to buy crimping tool and all that. Teflon tape of course is a must. Now I need to go to the chiropractor :-/