Black tank sensor?

TJ859 · 10-27-2019, 09:34 PM

New to forum recently bought a 2013 Cougar having trouble with the volume in
my black tanker sensor shows 1/3 when empty any help would be good Thanks in advance.

Chris P · 10-28-2019, 01:44 AM

Welcome from New Jersey, the sensors aren't 100% accurate, yours may just be dirty, fill the tank with water,add some Dawn dish detergent about 1/2 cup and calgon water treatment take the camper for a ride to swish the mix around and then flush the tank. Warm water wouldn't hurt either. Good luck.

Roscommon48 · 10-28-2019, 05:14 AM

read everywhere....YOUR SENSORS DO NOT RECORD CORRECTLY.

You just need to learn when to dump. Black water for us (2) can be up to 2 weeks before we dump.

Canonman · 10-28-2019, 06:12 AM

If your Cougar is equipped with a black tank rinse, use it to fill the black tank. Empty and fill again. It may take 2 or 3 rinse cycles to clean the "stuff" off the sensor. If that doesn't work, then the soap and water softener suggested by Chris is a good next step. Some folks have had some luck with a rinse wand that is used through the toilet to clean the sensors. As said, the sensors are not real accurate. But, ours reads empty after emptying the tank and gives us a good estimate of the fill level while we're camping.

Customer1 · 10-28-2019, 04:14 PM

Get used to it. Sometimes it might read full when empty, it's a flawed design but it's cheap to install.

Eventually you will get an idea of how long it takes to fill. You may be able to look in the toilet and see the contents.

Often the toilet will burp when flushing. If it does, get thee to a dump station. The reason it will burp is once the contents reach the bottom of the vent pipe, the vent ceases to work.

**flybouy** · 10-28-2019, 04:32 PM

The subject has been discussed at length in the past. Just click on the search and enter "black tank sensor" and you'll have plenty of reading material for this winter.
My take is about 50/50 on those reporting they're useless or they work "perfectly". Personally I think there's just too many variables to make a blanket statement. So read up, make notes and try some of the "remedies" suggested.

fjr vfr · 10-28-2019, 05:46 PM

I replaced my next to useless sensors with Horst Miracle Probes. They aren't perfect either, but much better than the button sensors that come with these trailers. Welcome to the Forum.

travelin texans · 10-28-2019, 07:59 PM

What does it indicates when tank is full? If yours works as well as all my past/present RVs it probably reads the same 1/3 when full.
Get yourself a clear fitting to place on your waste drain before adding the stinky slinky, this way you'll know when it's empty & don't bet the farm that it will ever be accurate when full.

wiredgeorge · 10-29-2019, 04:31 AM

Quote:

Originally Posted by fjr vfr

I replaced my next to useless sensors with Horst Miracle Probes. They aren't perfect either, but much better than the button sensors that come with these trailers. Welcome to the Forum.

My black tank idiot light has read full since buying the RV. I have replaced the sensors with Horst Miracle Probes, replaced the sensor pigtail wires and replaced the control board where the idiot lights are located. The resistance values (given to me by Horst customer support) are where they should be between the probes. The idiot light still reads full all the time. I gave up.

**chuckster57** · 10-29-2019, 04:45 AM

I must be doing something wrong. Every RV I have either owned or worked on has proper reading sensors in ALL tanks. Just sayin...

wiredgeorge · 10-29-2019, 05:00 AM

Quote:

Originally Posted by chuckster57

I must be doing something wrong. Every RV I have either owned or worked on has proper reading sensors in ALL tanks. Just sayin...

Makes me feel better hearing YOU don't have any issues. I guess I will just have to feel good about being good lookin and cool.

skids · 10-29-2019, 05:27 AM

Quote:

Originally Posted by chuckster57

I must be doing something wrong. Every RV I have either owned or worked on has proper reading sensors in ALL tanks. Just sayin...

Me too, mostly. We had a black tank sensor acting-up in our Jayco which was instantly fixed with a directional spray wand.

**JRTJH** · 10-29-2019, 05:46 AM

Quote:

Originally Posted by wiredgeorge

Makes me feel better hearing YOU don't have any issues. I guess I will just have to feel good about being good lookin and cool.

Possibly, Some people's "poop don't foul" (the sensors) and the rest of us, well: Not so much.....

travelin texans · 10-29-2019, 08:02 AM

I've owned 6-7 different RVs the last 40+ years & the sensors on all them worked great.......ONCE when new.

wiredgeorge · 10-29-2019, 01:17 PM

When I was a lad... ah heck, never mind; it has already been done 7 times in this thread alone. I am going to back out of this discussion and go look for my magic wand and see if I can take a shower at the same time as flushing out the tank bwhahahaha

**flybouy** · 10-29-2019, 02:08 PM

Quote:

Originally Posted by wiredgeorge

When I was a lad... ah heck, never mind; it has already been done 7 times in this thread alone. I am going to back out of this discussion and go look for my magic wand and see if I can take a shower at the same time as flushing out the tank bwhahahaha

Use plenty of soap and don't get upwind of the neighbors !

larryflew · 11-03-2019, 08:34 AM

Like the note on your mirror that says objects may be closer than they appear these should say level may or may not be as indicated.

dmorgan64 · 11-03-2019, 09:24 AM

The sensors are not accurate as mentioned! After I empty the tank, I put about a gallon of water in the tank, a cap full of Calgon Water Softener and a little bit of Dawn Dish soap. It is not perfect but I have good luck with this combo. It helps keep the sensors working (although no guarantee).

DDuncan51 · 11-03-2019, 09:44 AM

As long as the full sensor works you're good to go. Dump that is.

thefulminator · 11-03-2019, 06:56 PM

You probably have a combination of two different problems, sensors that are both misreading and inaccurate. I've had two different Outbacks and neither one had accurate sensors. There wasn't much I could do but live with it. I have also had times where completely empty tanks would read 1/3 or 2/3 full.
The misreading part I could do something about.

If I am having misreading problems I park the trailer with the offending tank full of clean water, add Thetford level gauge cleaner and let it sit for about a week. I'll tow it to the next campground and drain the tank. This has always worked for me.

As for the inaccurate sensors, with the tanks completely empty I've hooked up to city water and measured out 5 gallons at a time with a bucket filling with the handheld shower. I then dump the 5 gallons either down the bathtub drain or toilet depending on which tank I want to test and check the level on the control panel. From that I've learned that my "just full" 30 gallon gray tank will completely fit in my 25 gallon waste tote. Doing this test will let you know what full means and how much wiggle room you have once the full reading is reached.

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