Reply
 
Thread Tools Display Modes
Old 10-02-2019, 07:17 AM   #1
Junior Member
 
Join Date: Jun 2019
Posts: 6
Groaning noise while using black tank flush

Ok folks lets hear some possibilities. When using black tank flush there is a groaning noise when I have the water flowing to it. Anyone ever heard of this issue? Seems to be flushing but there is very little water coming out while doing so
__________________

36ckts is offline   Reply With Quote
Old 10-02-2019, 07:31 AM   #2
Site Team
 
Flybob's Avatar
 
Join Date: Oct 2014
Posts: 10,200
Could be an issue with the backflow valve restricting the water flow. Is the water pressure good?
__________________

__________________

2015 Freedom Express 248RBS
TV 2015 Silverado HD2500 Duramax
TST Tire Monitors
Honda 2000I + Companion
2 100W solar panels
Flybob is offline   Reply With Quote
Old 10-02-2019, 07:58 AM   #3
Trailer Park Supervisor
 
NJKris's Avatar
 
Join Date: Sep 2018
Location: Northern NJ
Posts: 1,810
Mine makes groaning noises too, but water is definitely going into black tank. Check the hose going into the black tank underneath your trailer, during my PDI I discovered the hose run was too short to make the bend, and it was badly kinked. The dealer fixed it by putting hose clamps over the kinked area to squeeze it round.
__________________
2019 Rockwood Geo Pro G19FD w/off road package
2015 Ford F150 XLT Super Cab 4x4 V8
NJKris is offline   Reply With Quote
Old 10-02-2019, 08:11 AM   #4
Brake is on left
 
The Evil Twin's Avatar
 
Join Date: Jul 2019
Posts: 191
Mine does it. I thought it was normal.
I have not traced out the line but I assumed it was the BFP. There is no shortage of flow to the tank judging by what it breaks loose in there.
The Evil Twin is offline   Reply With Quote
Old 10-02-2019, 08:19 AM   #5
Head Rambler
 
Join Date: Mar 2008
Location: Southwest Alabama
Posts: 6,788
Some black tank flushes are 'Tornado' style where the head spins when it's flushing and they'll buzz or hum when running.

Looks like you have a Cedar Creek 36CKTS, but you don't say what year it is in your signature or profile so I don't know if it was installed at the factory or was an add-on.
__________________
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!
Bama Rambler is offline   Reply With Quote
Old 10-02-2019, 09:08 AM   #6
Junior Member
 
Join Date: Jun 2019
Posts: 6
It's a 2014 CKTS and it's factory installed
36ckts is offline   Reply With Quote
Old 10-02-2019, 09:08 AM   #7
Senior Member
 
Join Date: Feb 2017
Posts: 133
I have the factory flush, and I also get a groaning sound. No kink in the hose or issues routing issues. I did, at one point, have the flush clog. I took it apart and enlarged the pin holes that it uses to spray the tank, re-installed, and there is less groaning now. Now, I mostly hear water splashing on the side of the tank.
__________________
2017 F350 Powerstroke DRW 4x4
2013 Cedar Creek 36CKTS Custom
aknavy is offline   Reply With Quote
Old 10-02-2019, 09:09 AM   #8
Trailer Park Supervisor
 
NJKris's Avatar
 
Join Date: Sep 2018
Location: Northern NJ
Posts: 1,810
Evil Twin, based on your Avatar, I think you were following me pretty close on the Tail of the Dragon! Let you pass and then tried to keep up with you.....nope.... lol.
__________________
2019 Rockwood Geo Pro G19FD w/off road package
2015 Ford F150 XLT Super Cab 4x4 V8
NJKris is offline   Reply With Quote
Old 10-02-2019, 09:18 AM   #9
Junior Member
 
Join Date: Jun 2019
Posts: 6
I wondered about it being clogged. I had one on my Sandpiper years ago that was an add on and it clogged. That was fun getting to. I'm guessing I'll need to pull the under belly to get to it.
36ckts is offline   Reply With Quote
Old 10-02-2019, 10:36 AM   #10
Brake is on left
 
The Evil Twin's Avatar
 
Join Date: Jul 2019
Posts: 191
Quote:
Originally Posted by NJKris View Post
Evil Twin, based on your Avatar, I think you were following me pretty close on the Tail of the Dragon! Let you pass and then tried to keep up with you.....nope.... lol.
LOL, at the Tail it would have been on the "Moose". The bike in my avatar is race only. If you ever go to NJMP in Millville you'd see it This is the street bike:
Attached Thumbnails
Click image for larger version

Name:	IMAG0760.jpg
Views:	50
Size:	398.9 KB
ID:	216435  
The Evil Twin is offline   Reply With Quote
Old 10-02-2019, 11:05 AM   #11
Trailer Park Supervisor
 
NJKris's Avatar
 
Join Date: Sep 2018
Location: Northern NJ
Posts: 1,810
I"m always happy to see bikers 'taking a knee' on the Tail. I groan when I get stuck behind regular bikes that can't go faster than my Corvette!
__________________
2019 Rockwood Geo Pro G19FD w/off road package
2015 Ford F150 XLT Super Cab 4x4 V8
NJKris is offline   Reply With Quote
Old 10-02-2019, 01:35 PM   #12
Junior Member
 
Join Date: Apr 2015
Posts: 18
Groaning While Flushing

I have a 2015 Cedar Creek Silverback. It makes a loud humming noise while the black tank flush is operating. I guess it could be called a groan.

I always attributed it to the anti-siphon valve and took it as a sign that everything was working properly. The valve was originally installed backwards at the factory and never made a sound when I tried to flush. But it wasn't allowing the water to pass through to the black tank either.

I think you're OK if the results of the flush are satisfactory and there are no leaks.
plymaniac is offline   Reply With Quote
Old 10-02-2019, 04:19 PM   #13
Junior Member
 
jeff_s's Avatar
 
Join Date: May 2015
Posts: 13
Groaning noise while using black tank flush

If very little water is coming out I would first look at the Check valve/vacuum breaker. It's usually a lot easier to get to than the spray head in the tank itself.

I had the same problem a few months ago and replaced the plastic valve with a brass check valve.....problem solved. Much more water now and better flushing action. See picture of the check valve I installed. I also have a new brass vacuum breaker but haven't installed it yet.
Jeff
Attached Thumbnails
Click image for larger version

Name:	Screenshot (41).jpg
Views:	57
Size:	94.5 KB
ID:	216467  
__________________
2016 Wildcat Maxx 262RGX
2012 Ford F350 6.7L PSD
jeff_s is offline   Reply With Quote
Old 10-02-2019, 05:01 PM   #14
CGK
Camping with Labs
 
Join Date: Jan 2019
Location: Jarrettsville, MD
Posts: 88
We also get the "groaning" noise when we flush; and there is plenty of water going into the tank, judging from the amount of water flowing out of the tank while we are doing the blackwater flush (we use a clear elbow so I can see the results of my labor). So the noise and reduced water flow may not be related in any way, based upon our experience with the last two TTs.
__________________
Chris, Paula, & camping Labs, Shasta & Cammie
2005 Yukon XL 2500 with 8.1 Engine, Allison Transmission, and 3.73 Axle Ratio
2019 Rockwood Signature 8335BSS
CGK is offline   Reply With Quote
Old 10-02-2019, 05:38 PM   #15
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 5,191
Based on my experience over the years with "groaning" in water pipes, it comes from low flow and a valve that has a loose stem or washer. In the case of the tank flush the back flow valve might be causing the groaning because of a restriction downstream. Not enough water is flowing to keep the valve completely open and the internal spring is causing the valve mechanism to "flutter".

Just like the water faucet that "groans", it will go away if more water can pass through.

If there is a poll on what might be the cause my vote goes to a restriction in the form of a kink in the lines between anti-siphon/back flow preventer/check valve and tank. Could also be plugged orifices in the actual flush head itself.

Needs more water flow to hold the check valve more wide open.
__________________
Sami. my Shih-Tsu "Co-Pilot" R.I.P
Politically Incorrect since 1943
"Sometimes you're the dog, sometimes you're the tree"

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is offline   Reply With Quote
Old 10-02-2019, 08:13 PM   #16
Junior Member
 
Join Date: Apr 2015
Posts: 18
Groaning Follow-Up

To the original poster,

I overlooked your statement that very little water was coming out of the black water tank during the flush. That may change my earlier comment that all may be well even with the groaning sound.

Assuming a typical water hook-up, if your flush outflow is just a trickle it's either a bad anti-siphon valve, clogged or broken spray nozzles or a kinked water supply line. You should be able to trace the water supply line from the city connection to the anti-siphon valve to find any kinks. The valve is easily replaced if you can work with Pex fittings. Bad spray nozzles are too big and dirty of a project for my pay grade.

All that being said, when I first operated my black water flush system I was surprised at how little water output there actually was during a flush. But I could see solids being removed. The outflow is much less than a normal gravity-fed tank dump. The diameter of the water supply line is just not big enough to produce a bigger flow.

I run my flush for an hour or more until the outflow is crystal clear. Where I camp the water doesn't cost me a thing.

Good luck. You will solve this problem.
plymaniac is offline   Reply With Quote
Old 10-02-2019, 10:28 PM   #17
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 5,191
Quote:
Originally Posted by plymaniac View Post

I run my flush for an hour or more until the outflow is crystal clear. Where I camp the water doesn't cost me a thing.
Wow, I thought I was flushing my tank for a long time when I let the flush run for 10 minutes.
__________________
Sami. my Shih-Tsu "Co-Pilot" R.I.P
Politically Incorrect since 1943
"Sometimes you're the dog, sometimes you're the tree"

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is offline   Reply With Quote
Old 10-03-2019, 01:14 AM   #18
Member
 
Join Date: Aug 2018
Location: Alberta, Canada
Posts: 52
Quote:
Originally Posted by 36ckts View Post
Ok folks lets hear some possibilities. When using black tank flush there is a groaning noise when I have the water flowing to it. Anyone ever heard of this issue? Seems to be flushing but there is very little water coming out while doing so
You are lucky to hear a groaning noise.
My first attempt flushing our tank did not go so well. The black flush check valve was installed backwards. Swung the valve to the correct flow path and still did not work. Took the check valve apart and removed the ball for a flush. Made my own black flush check valve until end of season then took the RV back to dealership for this and other repairs.
Flush is working well now.
The sound I hear is water spraying into tank. Suspect I only have nozzles and not twirlers.
Arnie M is offline   Reply With Quote
Old 10-03-2019, 04:47 AM   #19
Senior Member
 
Chris Pastuzyn's Avatar
 
Join Date: Jun 2019
Posts: 171
Had the same issue on my 2511s, traced it back to the spring on the backflow preventer, was able to get it to work by playing around with the spring but I'm going to replace it, The spring is way to stiff. IMO
Chris Pastuzyn is offline   Reply With Quote
Old 10-03-2019, 08:26 AM   #20
Senior Member
 
Join Date: Jun 2016
Location: Mid Michigan
Posts: 772
Hydraulic check valves and relief valves make a groaning noise.
__________________

markb422 is offline   Reply With Quote
Reply

Tags
black, black tank, black tank flush, flush, noise, tank

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 05:05 AM.


×