Galley Holding Tank does not empty

[johnat4mc]

I have a 38 ft Cedar Creek 5th wheel and it appears the Galley holding tank does completely empty. The monitor on the panel shows that it is always either 3/4 for 4/4 full and I have to dump it frequently to keep water from backing up in the kitchen sinks. I attached a water hose to the outside sewer cap, opened the galley valve and back filled the tank till water backed up into the kitchen sinks then opened the cap to allow the water to drain rapidly. May have helped a tiny bit but not much. I would appreciate any suggestions.

Thanks, John

[CHICKDOE]

i'm not the expert here, others may have better ideas. but it is a gray water. i would suspect that it is faulty sensors. it should not be clogged like a black tank. but then again the gray valves and drains are a smaller diameter than the black so they could clog easier. but still, if you opened the drain and just left it open for some time i would still expect it to drain. try that and let it drain overnight or so and then check the lights to see if they are still showing a full tank.

[BuzzWolfAR]

My galley sensors take hours to adjust after I dump gray water. I suspect they get grease on them which inhibits their operation. Flushing a couple of times with water and detergent may clean it.

Just a hunch. Flushing helped mine. I also always but some fabric softener in the empty tank with a gallon of water, after dumping.

[johnat4mc]

Thanks for the suggestion. I will try the fabric softener approach.

John

[Mr. Dan]

Originally Posted by CHICKDOE

i'm not the expert here, others may have better ideas. but it is a gray water. i would suspect that it is faulty sensors. it should not be clogged like a black tank. but then again the gray valves and drains are a smaller diameter than the black so they could clog easier. but still, if you opened the drain and just left it open for some time i would still expect it to drain. try that and let it drain overnight or so and then check the lights to see if they are still showing a full tank.

It's not merely faulty sensors... else the gray water wouldn't back up in the sinks.

[mecd]

Agree with Mr. Dan. I had a similar problem in that the gauge always showed 1/3 to 1/3 full even with the gate valve to the galley tank open on my 2015 Cedar Creek. If I left that tank open and the cap off when leaving a campground, very shortly the rocking motion of moving emptied the tank completely. Don't recommend that but I proved it was not a faulty gauge or dirty sensors. Problem being my Auto Level was off and after getting level recalibrated/trued, it has been fine. Not sure that is part of your problem. Might need to remove panels under front where tanks are located to determine how good the gate valve is working. Just be careful putting screws back in the panels to hit the movable wooden slat that the support the panels.

I never found any additives of any nature did anything to clean gauges; but, an RV Tech Manager who has been RV'ing for the best part of half a century including with his parents suggested to always leave the gray tanks open when at a full service campsite to especially take stress off of grey tanks connections at tanks that can separate even a little bit and allow odors to spread through RV. I have been doing that for at least 2-years and no odors anywhere. All his other recommendations, etc. have been bang on. I trust him. For what it is worth.

[Paulie1138]

My neighbor had an experience similar to yours. Showed up after almost 3 years of owning it. I took a waterproof (29.00 Amazon) boroscope attached to my iPad. Snaked it up into the grey tank. Turned out, he had the plastic plug blocking the tank exit. I think it came from where they cut the drain from the sink. It had wedged itself at the bottom 2/3's just inside of the tank opening. Cut the pipe close to the tank, pulled it out, put in a black female/female coupler. Glued it up. All is well in drain-O land!

[The Lieutenant]

Have you ever had an issue with the valve locking in the open position where your pushing and pushing and it wont go in then all the sudden it mystically goes in?

Based on what you are describing, I wonder if you have a wood chunk from fabrication blocking your outflow. Your backflush temporarily solving the problem is leading me in that direction.

[brookstone345sa]

Roof vent may have slipped down into tank or plastic plug from hole drilled blocking drain valve

[johnat4mc]

Thanks for all your replies. Sounds like I may need to get a scope up there and take a look.

Thanks, John