# Black Water Tank Sensor



## Fletch (May 16, 2008)

Hi everyone,
Hope all you outbackers are having a safe and fun summer.







I have a question about our black water tank sensor. Two weeks ago we went camping at a KOA in Rochecter NY. Great place to stay.







We were pulling out and I had to stop at the dump station because our site only had water and electric. The station was at the bottom of a small hill. So the TT was going uphill a little. I emptied out the blackwater, then flushed with the grey. I had now problems. This week we went out again with out Outback 26rs and the site was almost perfectly level. Backed in, just cranked the jack up and pulled the truck out and lowered back down. Well we got set up and I notice that my black water tank showed 2/3 full. So after a day I let if get to full and then pulled the valve to empty it. After no sounds of anything coming out after a while, I check the sensor and it still read 2/3? Im think something got stuck on the sensor and I was going to get some calgon water softner to put in it and see if that loosens anything up. Has anyone had this problem? Also had a slight leak from tv antena on a very rainy day. Only had it up once sense we had the TT and noticed water dripping from it. So I put it up and turned the antenna and that seemed to work. Not sure what was going on with that?
Any Suggestions would be great.
Thanks 
Fletch


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## Eagleeyes (Aug 1, 2007)

Fletch said:


> Hi everyone,
> Hope all you outbackers are having a safe and fun summer.
> 
> 
> ...


Well, sometimes a little plastic piece that was the cutout gets stuck...you'll need a snake more than likely...


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## MaeJae (May 12, 2005)

First off... we will not be posting pictures of the inside of the black tank.... LOL









The leak you have is more than likely the "boot" that covers the antenna wire. It has
come loose. You will need to just take a look-see and slide it back down to position.

MaeJae


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## Moosegut (Sep 24, 2005)

My black tank gauge almost never reads empty. I have often looked through the toilet (with the water supply turned off) at an empty tank (just a half inch or so of fluid) only to have my gauge read a third or 2 thirds full. You are correct in that something is probably stuck on the sensor. The only time mine ever reads empty is after I have gotten out the wand and cleaned the tank. It's nothing to worry about.

You'll get a feel for the tanks after some use. My gauges on all three tanks are far from accurate. The sensors are put in the tank by someone who probably just eyeballs where to drill the holes. You would think a template for gauge placement on a tank would be in order but I have seen such a discrepancy in readings between mine and many other Outbackers that it leads me to believe that the sensor placement is arbitrary at best.

So far as the leak goes, it is time to get on the roof and check that out. Look at the base of the antenna and make sure the caulk is intact. That's something you want to stop immediately. If you only noticed that it's leaking when it rains hard - IT'S LEAKING! That's something you want to stop right away.


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## Nathan (Jan 2, 2007)

Yep, probably tissue on the sensor. I got a piece on this summer and it would read 2/3 full. An extensive series of flushings seems to have taken care of it. If in doubt, shine a flashlight down the toilet as you flush it. That should give ou a good view of the real status.


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## tdvffjohn (Mar 10, 2005)

Probably a piece of paper laying across the sensors. If you are camping and have sewer at the site, fill the black higher with chemicals in it, let sit for a while(1/2 day), the paper will probably disolve off. Otherwise sooner or later it will come loose.

John


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## webeopelas (Mar 11, 2006)

Or, it may never come loose. My Outback went to 2/3 and stayed there. Never did get them to read accurately.

I just looked down the toilet and determined when it was time if we were staying for an extended period. I even bought a wand, and that didn't help. Did clean the tank better, but didn't help the guage.

They are just one of those things that can easily stop working, but it not worth the effort to fix it.


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## nynethead (Sep 23, 2005)

mine has been this way for the past year and never changes.


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## BoaterDan (Jul 1, 2005)

The sensors are notorious for doing that. There are threads with various solutions around here, including the water softener as you mention. I've never had an issue with the black tank getting full, so I don't even bother looking at it. About the only one out of the four that still works and seems to indicate anything useful is the freshwater.


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## Lady Di (Oct 28, 2005)

Our sensors are mostly all off on their readings.

If we can see the 'stuff' the black is full, if the bathtub backs up the grey is full, if the pump won't pump any water the fresh is empty.


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## pintoplumber (Nov 4, 2007)

Our sensors were reading full this weekend when we arrived and remained full after emptying. Our sewer at home is between the curb and sidewalk, so I hooked up to that and made a fitting for the end of the garden hose. Put it down the toilet and sprayed in the direction where I know the sensors are. It now reads empty. My buddy says he wraps a rubber band around his garden hose sprayer and puts it down his toilet. Dennis in PA


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## Camper Louise (Aug 7, 2004)

When this happens to us and the dump station is busy, we usually go home fill black tank with fresh water through the toilet with a garden hose, let it sit a day and go dump again and the sensor is now clear. If the dump station is empty we just do it there. We have learned in 4 years about how long we can go before needing to empty so we do not rely on the sensor too much. It is aggravating though. Our black tank just gets cleaned out more often.


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## MJRey (Jan 21, 2005)

I don't worry about the black tank readings too much. We've gone just over a week with the whole family and not filled the tank. As long as the trip is less than a week aI don't worry about the black tank at all. The grey tank is the one that is always filling up fast for us.


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## mmblantz (Jul 1, 2007)

pintoplumber said:


> Our sensors were reading full this weekend when we arrived and remained full after emptying. Our sewer at home is between the curb and sidewalk, so I hooked up to that and made a fitting for the end of the garden hose. Put it down the toilet and sprayed in the direction where I know the sensors are. It now reads empty. My buddy says he wraps a rubber band around his garden hose sprayer and puts it down his toilet. Dennis in PA


Does he reuse the sprayer after he does this?


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## daslobo777 (Mar 24, 2007)

After learning from previous posts on this site I always use the following plan and after 1-1/2 years all sensors are working fine:

1) Always use Borox Water Conditioner (1.5 C in black, 1 C in gray),
2) Always clean black with a wand (4-5 fill/dump cycles) after each trip.
3) Every other trip I add 2 bags of ice cubes in 1/2 full black before breaking camping for some aggetated cleaning during the drive home.


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## jitch388 (Apr 19, 2008)

Ours has shown 2/3s full since our secnd trip out. I put some borax in it to see if that will help. Not to worry if it doesn't. We know about how much is in there most of the time.


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## OregonCampin (Mar 9, 2007)

We had this happen after our last trip - even with ice in the tank for the ride home... we dumped and then went home and used the wand - we then added the water softener and let it sit until our next trip. We used the tank on the next trip and then dumped and all was good.

I think the ice does help - this was the first time we have ever had that happen. This trip was a six day wilderness trip with no other facilities, so the tank was probably used more than ususal.


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## Stan (Aug 9, 2006)

Wow..you guys are amazing..great advice. We had problems believing our sensors on our 2 week trip to the Adirondacks then Indiana Dunes. I'll try the solutions recommended.

Where are the sensors located?


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## Jwood0129 (May 5, 2008)

Hello, 
Alot of suggestions of wands and refilling the tank works well. Another trick is something from Camping World that allows you from the black water connection to backfill and flush the tanks. I do this every three outings and it has a nice clear area so you can see the "not so clean" water change to clean water so you know your tanks are empty and it also clears the sensors well.


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## 153Syr (May 9, 2007)

Others may have added this, but I'll chime in. Download and read the "Holding Tanks 101" posting. Lots of good information there. I have been using a clear plastic 45-degree elbow between the trailer and the sewer hose. That helps me see when the tanks stop flowing. I also use a Quickie-flush for the black tank. There are several postings about installing that. The same article also suggests a solution of 2 cups Calgon to 1 gallon of hot water added to an empty black water tank. I did that & think it helped.

After the tank is empty, make sure you add a couple gallons of water along with your non-formaldehyde tank additive (Odorloss or Thetford). In hot weather, you don't want problems here, and lots of water in the tank helps. Before you head home (or to the next camping spot) adding a 10-lb bag of ice to an empty tank will help break up solid matter. The ice moves around as you drive.

Good luck with it.
--Gary


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## BoaterDan (Jul 1, 2005)

Lady Di said:


> Our sensors are mostly all off on their readings.
> 
> If we can see the 'stuff' the black is full, if the bathtub backs up the grey is full, if the pump won't pump any water the fresh is empty.


Yep, I use the same technique most of the time.


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