Black tank flush

[Darrin1221]

We purchased a new 2017 Precept 31U and when I hooked up a hose to flush the black tank I'm getting a very small amount of water going in. The only sound is a very slight hissing sound and when I looked down thru the toilet I can't hear anything. After leaving it hooked up for a good period of time there was a small amount of water in the sewer hose.
Is this normal? I'm I missing a step other than hooking up the hose and turning on? My old Allegro would flood the black tank when doing this.
Thanks for any input on this matter.

[bansai]

There is a check valve incorporated in the black tank flush plumbing to prevent back flow. I'm guessing it has failed somehow. See if you can locate it, and inspect / remove / replace.

[Darrin1221]

Will do, thanks for the info.

[DonaandDon]

Most connections have a protector screen/rubber gasket where you connect the flush hose. It may need cleaned out..

[norty1]

Does black water come out when the tank is full and the valve is open?

Just asking because on a previous camper the pull handles were mis-labeled.

[DonaandDon]

No! It's usually a brown, until cleaned out. OBTW, how hot does your hot water heater heat your already hot water?

[Darrin1221]

No problems draining the black water tank. Bansai mentioned a check valve, I am thinking it was installed backwards.

[Darrin1221]

Checked it. It is clean. Thanks!

[norty1]

Originally Posted by Darrin1221

No problems draining the black water tank. Bansai mentioned a check valve, I am thinking it was installed backwards.

I think he is talking about the tank flush which does have a back flow valve. The black tank drain does not have any check valve.

Seems like we are not all talking about the same thing.

http://rvtipoftheday.com/rv-trailers...ystem-problem/

[bansai]

Originally Posted by norty1

I think he is talking about the tank flush which does have a back flow valve. The black tank drain does not have any check valve.

Seems like we are not all talking about the same thing.

RV Holding Tank Flush System Problem

Exactly.

I'm presuming the problem with water not getting into the tank, via the black tank flush 'plumbing' has to be related to the check valve installed there.

If the OP was having issues draining the black tank under all scenarios, then it has nothing to do with that system.

One other question that popped up in this thread (thread jack alert )
how hot does your hot water heater heat your already hot water???

Exactly the same way it heats your cold water. The end result is the same. It takes me 30 minutes to heat 6 gallons of cold well water to scalding temps. If the water is already 'Hot', it takes a little less time.
/threadjack complete.

[norty1]

I had a drippy leak on the tank flusher check valve on a OB that I had the first time I used it. If I remember it was right near the water inlet.

If I ever installed one like the one in my link, I would purchase a check valve and install it somewhere in the flusher line.

[Darrin1221]

Yes it is the black tank flush. Wish me luck finding the check valve and being able to get to it.

[Darrin1221]

Found that the water line for the black tank flush was kinked. Was able to cut out kink and insert an elbow. Not easy to get to but now works great.
Thanks for everyone's input on this.

[JFlightRisk]

Originally Posted by Darrin1221

Found that the water line for the black tank flush was kinked. Was able to cut out kink and insert an elbow. Not easy to get to but now works great.
Thanks for everyone's input on this.

Good job! Another Happy Camper!

[Dave55]

Darren, where did you find the kink? I have the same problem with the same coach. Did you also find the check valve?

[Darrin1221]

Where you hook up the water hose to the black tank flush, look behind that connection and follow the water line as it winds around. There are a lot of water lines to deal with in a small area so it is not real easy to see but be patient. I would bet you have same problem.
I never did find a check valve.

[Darrin1221]

Just saw your other post. It may be the valve since it was working. Mine never did work.
I will be interested to see what you find.
Good luck!

[Dave55]

Jayco motorized division is normal very good, but not in this case. They told me there is no check or anti-syphon valve. They thought it could be a pinched line. I found the anti-syphon valve under the bathroom sink ( see picture ). It was stuck closed. Repair it by using garden hose. When operating correctly, the valve will rattle when you shake it.
But that was not the problem! I disconnected the line-screw off at the black water tank (it is located at the rear of the tank and can be reached through the dump valves side compartment and above the macerator hose compartment). I had full flow of water with good pressure. I gently probed the inlet into the black water tank with a 2" screw driver and felt an obstruction. Ran more water with the line disconnected but aimed at the inlet. Probed again and no obstruction. Connected line and tested system. It started with a low flow, but within 2 minutes I could good spraying action.
2 possible causes: 1. We have always dumped the black water at the 2/3 full level. It's possible some debris might have clogged the spray head. 2. There might have been some type of debris in the line at the connector.
Other people have complain about the cheap anti-syphon valve. I agree. I'll be looking for a good replacement. It should have 1/2 male threads.
PROBLEM SOLVED.

[Darrin1221]

Thanks for the info and picture. GLad you got it going.

[nalasha79]

I can't see the picture.. I am interested in checking the anti-syphon valve under the bathroom sink. I have noticed gurgling in my drains. Please help.

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