Black tank level sensor

[raul]

We dumped the black tank, but the level indicator still reads 2/3 full. We can flush the toilet and water drains out with no solids.Any suggestions

[Summit1]

This is apparently a common occurrence with most self contained RV's. When you empty the black water tank, do the flush with water as recommended by the manufacturer, then (after draining that "flush" water and debris from the black water tank, put a few gallons of clean water into that tank via the flush inlet. That small amount of water sloshing around as you travel after tearing down may very well clean the sensors inside the tank.

I am wondering if emptying a gallon of dish soap water would help as well, or if that would leave a soap scum/film inside the tank and on the sensors. Have not done that yet... just used water and a couple of ounces of the enzyme stuff.

[Gearitis]

Not unusual IMO. Clean the tank well by filling as full as possible, then drain with clean water. You may even fill, let sit a bit and drain. Do it several times. You may want to fill it about 3/4 full, drive around and then dump and fill and dump. Probably tissue or other material on that sensor. There is also a device that connects to your black tank discharge, it is calledCamco 39062 Dual Flush Pro Holding Tank Rinser with Gate Valve where you can actually hook your non potable water hose and back flush. Water is your friend with waste tanks and lots of it.

[RSchleder]

Get used to it! We've owned 12 RV's and we've yet to have a black tank sensor work correctly after a few trips, even on 3 class A diesel pushers. I understand there are upgraded "level monitoring systems" that do work better than the factory systems but we've never felt the need to change.
My best advise is to pay attention to the way your toilet flushes. If you get a bubble or "burp", time to dump the black tank. No big deal, after a few trips you will get a feel for how long you can go without dumping.

[raul]

This a 2018 384qbok and this is only the second time we have dumped going to try plenty of water thanks for the advise also going to look to see if it has a tank rinser.

[RSchleder]

A tank rince system is definitely a PLUS. However, even thought I rinse our black tank for at least 15-20 min's after each flush, the monitor still shows 1/3 to 2/3 full. I do get peace of mind though as I know the tank is relatively clean when the rinse water runs clear as it flows through my clear elbow on the end of my dump hose.

[raul]

Thanks guys filled the tank up three times and flushed everythig out level indicator back to empty

[tbarb]

Glad you got it working.
For the future cleanings check this site for information on the GEO Method. Dawn dishwashing detergent and Calgon. Sounds like that has worked for some.

[BandJCarm]

Mine is as empty as my brain right now.........and reads 2/3 full.

Sensors get wet, I guess, and stay wet. Or something.

Should be a better way, but there ain't.

[Dan n Gerda]

It's a common problem you are having, even in brand new RVs. Often the sensor which is in the tank is simply wet and may take time to dry out! The best way to be certain is to turn off your water (and pump if on), take a flashlight, shine it into your toilet, and see if is full or not! If you can't do that, then there are better sensors you can install or have installed! Also, if your RV sits for long periods of time and you don't flush the toilet to keep it functioning right, the sensors might be very dirty and muck has hardened on them! When ours is in outside storage, we check on it a lot, run the engine, generator, a/c, heat, appliances on generator power, tires, look for critters in mouse traps (so far so good), run the water, and check all the closets! Words of caution! Don't let your Fresh, Black, or Green (joke) tanks sit empty! They can crack! We've learned this from other more experienced RVers! Before our FR, 2 years now and 2 Coast to Coast and back trips, we've tented in the USA and Germany, had an Apache Pop up taken all over the USA then donated to homeless after Andrew ravaged S FL, two VW Campers, and more! My German wife grew up camping with her parents every year in Italy! Our 2 adult daughters grew up camping! Same with our grandkids! Now it's RV time and we love it from our home base station! Dan & Gerda

[Swampy]

This is a very common occurrence

Originally Posted by raul

We dumped the black tank, but the level indicator still reads 2/3 full. We can flush the toilet and water drains out with no solids.Any suggestions

This is a very common occurrence. I suggest you treat the holding tank to a geo method prep while you plan for the next outing. Go to Walmart and buy a bottle of Calgon water softener and some cheap liquid laundry detergent. In a bucket , blend 2 capfuls of Calgon and 2 capfulls of the detergent and 1 cup of bleach in 2 gallons of warm water. pour it down the toilet and add another 3 gallons of warm water. Leave the mixture in the tank until the next time you go camping and fill the tank. The Calgon will make the tank inside walls very slippery and when you dump, the sensors should clean off. If you have a tank rinser, run this after the dump and dump again when the tank is full. When you are finished dumping and rinsing, you may want to treat the black tank again. This should keep the sensors working and the tank smelling fresh.
BTW, the Geo method also works on the Grey tank and will keep those sensors working, too.

Good Camping ...... Swampy

[DAISY BOYKIN]

Sensors after a couple years will become dirty & corroded, will not read correctly. I use dishwasher PODS, I drop 3 pods along with the orange powder for deodorizer each time I dump and flush tank. The dishwasher pods seem to do a fairly good job of cleaning sensors to enable them to read correctly.

[jtesta1]

I dont know whatever happened to the days when your crapper got full you emptied the tank .the sensors get plugged up with crap and most times flushing don't do nuttin.

[spaach]

I know everyone has their own way of dealing with this so here is the one we use at our shop with great success. Right before leaving for a trip we put about 5 gallons of water and a 40lb bag of ice down the toilet. While driving the ice is abrasive enough to scrub out the inside of the tank without hurting it or the probes. When we get where we are going and hook up it just dumps out the discharge like normal along with the sludge and buildup inside the tank. For the cost of a bag of ice it is totally worth a try.

[eye95]

Originally Posted by jtesta1

I dont know whatever happened to the days when your crapper got full you emptied the tank .the sensors get plugged up with crap and most times flushing don't do nuttin.

Cousin Eddie! How ya been?

[Mikep-sc]

Originally Posted by RSchleder

Get used to it! We've owned 12 RV's and we've yet to have a black tank sensor work correctly after a few trips, even on 3 class A diesel pushers. I understand there are upgraded "level monitoring systems" that do work better than the factory systems but we've never felt the need to change.

My best advise is to pay attention to the way your toilet flushes. If you get a bubble or "burp", time to dump the black tank. No big deal, after a few trips you will get a feel for how long you can go without dumping.

I agree with RSchleder about getting used to an incorrect black water tank (BWT) reading. When the manufacturers came out with the built-in BWT flush capabilities, I thought that would fix the problem - Wrong. When camping, I empty the tanks every three or four days or use the "bubble or Burp" method to determine if the tank is near full. The only useful purpose for the built-in flush unit (IMHO) is to fill the BWT with about a gallon or two of fresh water after emptying the tank.

[myredracer]

False readings are normal. In fact, if you don't have false readings, something is very wrong, lol!

A thorough rinse/flush and dump helps a lot. There are many shapes and configurations of holding tanks and some are easy peasy to flush and dump and some are not. A back flush elbow may or may not help. Same with an in-tank rinser. The sensors are a little round button about 1/4" dia. and they get gummed up with crud which needs to get cleaned off. Also, Horst Miracle Probes may or may not help.

It helps to fill the tank to full or near full before dumping. Some cleaners *might* help. Some claim the Geo method works well (do a google search). One or twice a year we use a little Liquid Drano as it does not attack metal or plastic - our owners manual actually says to use it. We have an in-tank rinser and I let it run for about 15 minutes or so while we are breaking camp.

After you have been RV-in' for a while, you kinda get used to knowing when the holding tanks need dumping. You can also look down the toilet to see where things are at. I installed a shutoff valve behind the toilet to stop the water flow when inspecting the contents.

Note well - always use plenty of water. Add about 3-5 gallons before use, don't skimp when flushing and fill the tank up just before dumping. Trying to conserve water just creates problems.