Black tank flush problem 16XRB

Javin · 07-07-2017, 09:53 AM

Hi all,

So we have only been out twice in our 2016 Jayfeather 16XRB, and both times i feel there has been a problem with flushing the black water tank. After emptying black then grey tanks, i re-open the black drain valve and put the water rinsing hose to the tank flush inlet and water alway seems to splash out at me and not go into the black tank. It seems like water is unable to go into the black tank flush inlet for what ever reason.

I have read the instructions which seem straight forward but i feel i must be doing something wrong. Above the tank flush inlet there is a "Caution" sign that reads,-"Do not use the tank flush valve unless the fullway termination valve is in the open position". I cant seem to find anything in the manual referring to "Fullway termination valve", what is this and what am i doing wrong? Hopefully once i figure this out its not too late to flush and clean out the tank since it has been drained but not flushed properally.

any help appreciated,
thanks!

Grumpy · 07-07-2017, 10:14 AM

Quote:

Originally Posted by Javin

Hi all,
I have read the instructions which seem straight forward but i feel i must be doing something wrong. Above the tank flush inlet there is a "Caution" sign that reads,-"Do not use the tank flush valve unless the fullway termination valve is in the open position". I cant seem to find anything in the manual referring to "Fullway termination valve", what is this and what am i doing wrong?

That's just fancy wording for the dump valve.

sennister · 07-07-2017, 10:17 AM

So the valve they are talking about is the Black Tank Dump Valve. They say to leave this open because you can't see what the black level is while pumping water into that tank doing the flush. If you got distracted with the dump valve closed you could fill the tank to the point where it is overflowing into the bathroom. I normally close mine and either watch it fill from the toilet or just wait a few minutes and dump again. Kind of like not wanting to dump black when not full, it does a better job of removing stuff when it is getting dumped when full.

As for why you can't get it to work is harder. Has it ever worked? It is possible that some debris as plugged up the nozzles. If that is the case I don't know how to unplug it. I guess you could fill it with water from the inside and let it soak for a bit. There are some chemicals (other than the standard ones) which are designed to break up deposits. That might help. I don't think they have a check valve on the hose connection but maybe that is stuck if there is one. Our new camper is the first we have had with a black flush.

oldmanAZ · 07-07-2017, 10:39 AM

Quote:

Originally Posted by Javin

snip...
put the water rinsing hose to the tank flush inlet and water alway seems to splash out at me and not go into the black tank. It seems like water is unable to go into the black tank flush inlet for what ever reason.
...snip

My black tank flush inlet has a hose connection. By 'put the water rinsing hose to the tank flush inlet' do you mean screwing the flush hose to the black tank inlet or are you squirting water through a hose into the flush inlet?

Javin · 07-07-2017, 10:41 AM

I just find it strange that water seems to be splashing out as if something is blocking the inlet. The inlet looks exactly like the fresh water tank inlet which i never have problems getting water into, it just flows right in. But this black tank flush inlet seems to be air tight or blocked in some way that is not allowing water to flow into it. If I cant figure it out perhaps a trip to the dealer service will be in order.

Javin · 07-07-2017, 10:45 AM

Quote:

Originally Posted by oldmanAZ

My black tank flush inlet has a hose connection. By 'put the water rinsing hose to the tank flush inlet' do you mean screwing the flush hose to the black tank inlet or are you squirting water through a hose into the flush inlet?

Both the dumping stations that i have been to just have a hose with a plastic tube on the end, so its just squirting water into the inlet the same way i have done with the fresh water tank. I have never tried screwing a hose to the black tank flush inlet because the dump stations have never had that type of hose to connect. Perhaps that would work if it was attached by screwing a hose to the inlet?

Also, it says in the manual to leave the black tank valve open but i'm guessing to properly flush it you should close it untill the tank is full and then flush it?

oldmanAZ · 07-07-2017, 11:22 AM

W*mart and Amazon (and others) have a device called a 'water thief' or 'water bandit'. It is a tapered, flexible 'nozzle' with a male hose thread at the end. You push one end over a hose with the threaded end connected to a hose, in this case, the black tank flush.

There is very little restriction through the flush system so, hopefully, it will take care of your issues. If it doesn't, then you may need to see if there is something blocking the flush on your RV.

The manual says to keep the dump valve open because they don't want to be responsible if you get distracted with the flush is running and dump valve is closed. That can create a very messy situation!

You're right about dumping the black tank when full. If you read postings on this site, you'll find most of us alternately open and close the dump valve, but trying to get the tank full could be tricky. Notice I'm not telling you to close the dump valve with water flowing through the flush system!

If you get a clear section for your sewer connection, you can see the difference as the black tank gets cleaner as you flush.

sennister · 07-07-2017, 11:23 AM

They say to leave it open because lawyers. They don't want responsibility if you over flow the toilet.

Yes the hose needs to screw into the connection like you would with city water.

Sent from my Nexus 6P using Tapatalk

bankr63 · 07-07-2017, 11:30 AM

Quote:

Originally Posted by Javin

Both the dumping stations that i have been to just have a hose with a plastic tube on the end, so its just squirting water into the inlet the same way i have done with the fresh water tank. I have never tried screwing a hose to the black tank flush inlet because the dump stations have never had that type of hose to connect. Perhaps that would work if it was attached by screwing a hose to the inlet?

Also, it says in the manual to leave the black tank valve open but i'm guessing to properly flush it you should close it untill the tank is full and then flush it?

This probably wouldn't work. Most black flushes have a sprayer head at the end inside the tank (it's a flush, not a fill). You would need some pressure to get the water to spray in the tank with any force. Suspect that water is just spraying back out because you are not screwing the hose on and pressure can't build.

I know the dump station we use most often has a nozzle for cleaning your stinky slinky like you describe, but you can unscrew that from the hose, and then screw the hose onto the flush. Haven't done this myself as I don't have flushing, but have watched others do it while we've been lined up.

Javin · 07-07-2017, 02:51 PM

thanks everyone, will try screwing on a water hose to see if that works.

cheers!

Upabreak · 05-12-2019, 05:30 PM

I have the exact same problem on a new 2019 Pinnacle. I tried the flush inlet today using a take off from the inlet regulated supply and had the black valve open. I did not notice any extra flow out of the black drain and then stopped the input and noticed a pressure build-up and water squirting back when I disconnected the input hose. I'd like to monitor this thread for any advice. Thanks.

gware · 05-12-2019, 09:03 PM

I had the same problem with my Hummingbird. It was obstructed with something. I winterize mine with air pressure from a compressor, so I attached the fitting with the shrader valve on the black tank flush fitting, set the compressor for 50 lbs and blew it out. There was something in it, I heard it when it popped out into the tank. It has worked fine since.

Upabreak · 05-20-2019, 08:17 AM

I tried again with the air compressor trick and noticed that there is a pressure of 7 psi - that is probably the sprayer end effect mentioned in this thread. I hooked the water back up to the inlet and did notice a water flow out of the tank and heard a noise of some forces water movement inside the camper. There was still some pressure and some water release when I removed the hose so I think that is just how it operates.

gware · 05-20-2019, 09:35 PM

You may have a kink in hose. See if you can follow it down and try to move it up and down a little.

Upabreak · 05-21-2019, 05:59 AM

I did remove a service panel to see what I could find and noticed that the hose had at least two small diameter angle connectors. I'll try again with moving the hose to relieve any possible kinks. I visit the camper about every other week. Thanks.

Brad81987 · 05-28-2019, 06:38 AM

The black tank flush should also have a backflow preventer. I've read stories of these being installed backwards at the factory, which would prevent water flowing to the tank sprayer. Our dealer tech that did our PDI with us even mentioned this and that he'd checked operation of the black flush on our unit.

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