Tank Gages Not Working Properly

RichRob · 02-24-2020, 10:23 PM

Both black and gray tanks seem to be giving a false reading. The Black is showing 2/3 full after emptying and the gray is showing 1/3 after emptying and leaving open. Both tanks seem to empty fully (contents flowing out with force then slowly stopping) and RV is pretty level. I have filled both tanks to capacity before emptying and have used the "tank wand" to spray the inside of black tank, but readings remain off. Any suggestions?

cavie · 02-24-2020, 11:11 PM

Non working tank gauges are something that sooner of later will bite everyone. It is something best ignored and learn to live with.

ducksface · 02-24-2020, 11:13 PM

The system they use to Guage the tank was invented alongside the steam engine.

There is little you can do as it relies on what are essentially barbs inside the tank and when anything hangs on them, they can't tell a hanging Chad from a full tank. The hanging Chad registers across little contacts just as a liquid level would.

If you're serious about a cure instead of a perfunctory fix, look at see-level and the other (maybe capacitance?) type systems which do not require holes and barbs.

Other than those systems, anything anyone tells you is just going to amount to how to wash toilet paper off of the barbs.

You're $300 to $800 away from a cure (mostly a cure. 10,000% better, but still not fail proof)

Lt Keefer · 02-24-2020, 11:16 PM

Waste tank gauges always seem to be a problem. I never look at mine, experience has taught me the wife and I can go one week between dumping.

Laco · 02-25-2020, 12:13 AM

Those gauges are notorious for not being accurate. I, like most RV'ers from experience just know how often tanks need to be dumped. You will develop a pretty accurate feel for that, quickly.

Bob Denman · 02-25-2020, 12:19 AM

The sensors get clogged up with.... Goop!
You can try cleaning them with the old cup of dishwasher soap,five gallons of water, and about five bags of crushed ice trick...

vkb · 02-25-2020, 01:22 AM

Quote:

Originally Posted by Bob Denman

The sensors get clogged up with.... Goop!
You can try cleaning them with the old cup of dishwasher soap,five gallons of water, and about five bags of crushed ice trick...

Yes...this helps/works...then in a few weeks you gotta do it again...
We, pretty much just know when it needs to be drained ….

Bob Denman · 02-25-2020, 03:45 PM

If you add a tank "washing" system (Like San-T-Flush; or something similar): it's easy to keep things nice and clean!

The_Breeze · 02-25-2020, 04:16 PM

Quote:

Originally Posted by Bob Denman

If you add a tank "washing" system (Like San-T-Flush; or something similar): it's easy to keep things nice and clean!

I have that. I usually flush until it runs clear and it doesn't seem to help. Black always shows full and gray 2/3. The only one that works properly is the fresh.

I don't think the effort and expense are going to be worth it.

Beau388 · 02-25-2020, 05:10 PM

Quote:

Originally Posted by The_Breeze

I have that. I usually flush until it runs clear and it doesn't seem to help. Black always shows full and gray 2/3. The only one that works properly is the fresh.

I don't think the effort and expense are going to be worth it.

Any thing that coats the probes will cause a false reading. We found putting about five gallons of water and 1/3 cup of dishwasher liquid soap in the tanks before leaving the camp ground will usually wash the probes well, as you wander down the pothole filled roads. The big problem is the gray water tank as soap residue and food grease coat the probes while sitting.

The Gritz Carlton · 02-25-2020, 05:10 PM

I've had the gauges misread just after dumping but a little later on they start to register correctly again. The "hanging chad" scenario best fits. Bob's solution works great. Every 4th or 5th dumping, especially when you're going to be running for a few day, pour the ice and soap in...let the motion of the ocean as you drive slosh around and knock "Chad" off his feet.

Bob Denman · 02-25-2020, 05:16 PM

After I dump the black tank: I put about a cup of dishwasher soap down the toilet.
I fire up the San-T-Slush, and let it run until I've probably got well over five gallons of sudsy water getting moved around in the tank.
Then it's a matter of repeated dumpings and rinsings until the water runs clear...

My sensors are "Springtime Fresh:!

RichRob · 02-26-2020, 10:45 PM

Thank you to everyone who responded. I am going to try adding Happy Camper to black tank, fill with fresh water, and let stay for several hours while we're off seeing the sites. If that doesn't work, I will try the ice cube solution. And if still no luck, I will live with it. For 8 years in my old trailer, I never had sensors, and I had no problems. It just irks me when these problems pop up in a fairly new RV (2018).

Bob Denman · 02-27-2020, 02:23 AM

Good luck! I hope that it makes you... Happy! [I]

.

abjbrtd · 02-27-2020, 02:57 AM

Quote:

Originally Posted by RichRob

Thank you to everyone who responded. I am going to try adding Happy Camper to black tank, fill with fresh water, and let stay for several hours while we're off seeing the sites. If that doesn't work, I will try the ice cube solution. And if still no luck, I will live with it. For 8 years in my old trailer, I never had sensors, and I had no problems. It just irks me when these problems pop up in a fairly new RV (2018).

We used "Extreme Cleaner by Happy Camper" it actually worked,
soap/water/ice didn't, hand held wand didn't and neither did the "geo method".

Amazon doesn't sell it anymore, where do you get it?

Sonny · 03-04-2020, 07:55 PM

Quote:

Originally Posted by RichRob

Thank you to everyone who responded. I am going to try adding Happy Camper to black tank, fill with fresh water, and let stay for several hours while we're off seeing the sites. If that doesn't work, I will try the ice cube solution. And if still no luck, I will live with it. For 8 years in my old trailer, I never had sensors, and I had no problems. It just irks me when these problems pop up in a fairly new RV (2018).

Might also try the Scott RV toilet paper. Watched a you tube video on this very subject and they tested several TPs. Scott melted better. After i started using it in my 2018 M29 it seemed easier to clear the sensors with the SanT Flush. Easy to get at Walmart.
Good Luck

rudyhehn · 03-04-2020, 08:25 PM

Agree with the above. My gray and fresh sensors are fine, but the black water tank often reads it is 2/3 full when it is empty. Not pooping seems like a solution but resultant bad mood not worth it. On the good side we have never had a problem with the black tank filling before the gray tank needs dumping.

Bob Denman · 03-04-2020, 08:25 PM

There's another thread discussing toilet paper, and it offers a bunch of possible solutions to this issue as well.

Mr.Good · 03-04-2020, 09:29 PM

Quote:

Originally Posted by RichRob

Both black and gray tanks seem to be giving a false reading. The Black is showing 2/3 full after emptying and the gray is showing 1/3 after emptying and leaving open. Both tanks seem to empty fully (contents flowing out with force then slowly stopping) and RV is pretty level. I have filled both tanks to capacity before emptying and have used the "tank wand" to spray the inside of black tank, but readings remain off. Any suggestions?

Our MH has the typical idiot lights - Empty, 1/3, 2/3, and full. As soon as the 2/3 light comes on, it's time to drain tanks.

DW's brother-in-law (an experienced class A owner), taught me early on, to not go to a full hookup site and just open the black tank valve and leave it. He said, "Always wait until you tank is 2/3 full before dumping, to get a better flow". IMHO, this also gives time for the tank chemicals to breakdown everything.

Ours has the SAN-T-Flush. I follow his advice, but do this whenever I dump. After opening the valve for the black, then opening the grey to sorta rinse everything out, I shut the grey, shut the black, turn on the water to the San-T-Flush and wait until the idiot light shows at least 1/3, if not 2/3. Then shut off the water to the San-T-Flush and open the black tank valve. When the water runs clear, then I am confident that the tank is pretty clean. Sometimes, I repeat. Haven't had a problem in 3.5 years.

99dart · 03-04-2020, 10:59 PM

Quote:

Originally Posted by The_Breeze

I have that. I usually flush until it runs clear and it doesn't seem to help. Black always shows full and gray 2/3. The only one that works properly is the fresh.

I don't think the effort and expense are going to be worth it.

Same here. We tried Boraxo, Zep, dishwasher powder, Dawn... Nothing cured it!

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