Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 03-02-2021, 06:58 PM   #1
Yearling
 
Join Date: Mar 2021
Posts: 5
Black Water Tank Level Sensors Screwy



In my first year full time on the road and have a persistent, possibly worsening issue with the black water tank. Specs on my 2020 Rockwood 2706WS (33 ft) say I have a 45 gallon black water tank. (Tech at dealer says it's much smaller). I always put in 4 caps of Tank Digest with a gallon of water to start and have inconsistent reading on my panel so can't tell level of liquid in tank. I've used the tank-wash/flush inlet for from 15 minutes to 2 hours. Filled the bowl multiple times for a "push" flush (valve open of course). when dumping, water starts to run clear within 5 minutes or less. It never reads empty, goes from 1/3 to 2/3 after 6 quick pees with minimal flush water. It can go for 4 days with 2 people using it, never reads full, but when "testing" to see if full light comes on, had sewage seeping from under toilet before indicator light shows tank is full. This issue has persisted from the time I first started using the camper. I will try putting a bag of ice down the shoot next timer I move to help dislodge any paper stuck on the sensors. Would like to avoid pulling bowl, opening underbelly and dropping the tank for visual inspection. Any similar experiences or suggestions?
GodsJarsOfClay is offline   Reply With Quote
Old 03-02-2021, 07:15 PM   #2
Senior Member
 
Cabinfever97's Avatar
 
Join Date: Jan 2018
Location: Summit Township
Posts: 721
I never trust the indicators, not even on a new TTs maiden trip. I keep an ear and eye when flushing. I can tell by the sound when the tank is getting full and with a flash light can see as well. Remember the tank is not very high. It gets its volume by the length and width. I flush the black tank a bunch as well. Not to keep the indicators working but to be sure the solids are gone and do not build up.
__________________
2019 Hemisphere 272RL
2015 Ford F250 6.2L
Hensley Hitch
Cabinfever97 is online now   Reply With Quote
Old 03-02-2021, 08:00 PM   #3
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,459
Next time you dump the tank put in a cup of Calgon (mixed with 1/2 gal of water) and 1/2 cup of laundry detergent. That will help clean the sensors while you are driving around.

I do that after every third to fourth dump and my sensors stay accurate.
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank (Two-GC2) - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is online now   Reply With Quote
Old 03-02-2021, 10:32 PM   #4
Yearling
 
Join Date: Mar 2021
Posts: 5
Thanks for the advice. Last time we broke camp we only drove a few miles to the next camping grounds. We did throw in a bag of ice, some Downy and some Dawn, (although probably not enough) along with an ounce of digest. Not much chance to get it all to swoosh around. It looked like it was a little better, but not really. I'll try your brands and quantities (proven history of success) on our next move which will be at least a 3 hour drive so I'll get more swooshing action then.
GodsJarsOfClay is offline   Reply With Quote
Old 03-02-2021, 11:42 PM   #5
Yearling
 
Join Date: Mar 2021
Posts: 5
My ears are'nt very pitch sensitive. When testing to see if "full" indicator came on, ended up with sewage leaking out from under toilet. Still couldn't see any liquid down the hole - just assumed it had overflowed. Could I have another problem there as well? There is no leakage when using the toilet - was only after about a week (just 2 of us).
GodsJarsOfClay is offline   Reply With Quote
Old 03-03-2021, 04:23 PM   #6
Senior Member
 
Adrian Gordon's Avatar
 
Join Date: Mar 2018
Posts: 365
My experience is that if your tank sensors (especially your black tank sensors) are working correctly, it is only because the Gods on Mount Olympus are too busy screwing up somebody else's day to bother with you. Don't worry, they will eventually get back to you, probably sooner rather than later.
__________________
2018 Coachmen Leprachaun 210RS with DW, Nanuq the Samoyd puppy and the cat.
Adrian Gordon is offline   Reply With Quote
Old 03-03-2021, 05:11 PM   #7
Senior Member
 
DouglasReid's Avatar
 
Join Date: Jun 2016
Location: Maurice, LA
Posts: 3,419
This will be tedious but it will confirm the volume of your tank.

1. drain the tank completely.
2. get a 5 gallon bucket fill it and pour the water into the toilet.
3 after each bucket full look at the sensors to see what the reading is
4 do this until the tank is full (water running on the floor would be a good indication or you should be able to see it when the ball valve is open by looking down into the toilet)

The sensors are notoriously unreliable for a number of reasons, The location of their placement on the side of the tank is one reason for their inaccuracy.

If it never reads full I would suspect that particular sensor's wire is broken or off the contact on the outside of the tank.
__________________
2012 Wildcat Sterling 32RL, Gladiator Qr35 ST235/85R16 Load rating G, TST 507 TPMS w/ Flow-thru Sensors & Repeater, Reese Sidewinder 16K Pin Box, PI EMS HW50C
2008 Chevy Silverado 2500HD CCSB LTZ Diesel, Fumoto Oil Drain Valve, Turbo Brake activated, 39 gal Aux Tank W/ Fuel Pump transfer, Air Lift Loadlifter 5000 air bags.
DouglasReid is online now   Reply With Quote
Old 03-03-2021, 08:10 PM   #8
Just as confused as you
 
Scrapper's Avatar
 
Join Date: Aug 2013
Location: south central Wisconsin
Posts: 4,834
Quote:
Originally Posted by GodsJarsOfClay View Post
My ears are'nt very pitch sensitive. When testing to see if "full" indicator came on, ended up with sewage leaking out from under toilet. Still couldn't see any liquid down the hole - just assumed it had overflowed. Could I have another problem there as well? There is no leakage when using the toilet - was only after about a week (just 2 of us).
Sounds like you have the infamous Dometic 300 toilet. They are made from sections of plastic fitted together that have a record of leaking or smelling badly. Call Dometic and ask for a 310 series toilet which is an almost direct drop-in replacement.

The toilet will burp when your black tank gets near full while you flush it.

Always start with 5 gallons of water in your black tank along with the chemical of your choice. Anything less is not enough to slosh onto the sensors while driving.
__________________
Richard & Jill
2014 Flagstaff 832IKBS Classic Super Lite
2018 Silverado 1500 Crew Cab Z71 4WD All Star Edition
Camping since 1989
Car Shredder Op/Tech, Scrap Metal Recycling - retired
DW says I'm nuts, the bolts have been missing as long as we've known each other.
Scrapper is offline   Reply With Quote
Old 03-03-2021, 09:23 PM   #9
Senior Member
 
Join Date: May 2017
Location: Crowley, Texas
Posts: 128
Black Tank Levels

Count me among those who have never had an accurate reading of my Black Tank level in my Class A. In addition to having the tank level indication problem, it also affects the operation of the Thetford electric toilet in the main bathroom. When the Black Tank level indicates full, a signal is sent to the Thetford toilet preventing it from flushing!

The lowest level on the Black Tank I have ever seen is 1/3 full!!
LannyCox is offline   Reply With Quote
Old 03-03-2021, 09:41 PM   #10
Wanderluster
 
JACA's Avatar
 
Join Date: Feb 2021
Location: IL
Posts: 88
The #1 Rule that all RVers should learn:

Never, ever trust any tank level sensor/indicator lights.

I've had 4 different RVs - none of the tank level indicators were ever accurate enough to trust, even when they were brand new. At best, they might give you a ballpark figure - somewhere between empty and full.
__________________
John and Anita (Both Retired US Army/Law Enforcement)
Dynaquest 340XL (AKA Mobile Command Post)
Jeep Wrangler Unlimited
www.instagram.com/operation.wanderlust
JACA is offline   Reply With Quote
Old 03-04-2021, 10:43 AM   #11
Member
 
Join Date: Apr 2020
Location: Michigan
Posts: 72
I have a 2019 Class C. I started taking showers in it last year. I found my grey water sensors did not work well. I went to all the connections and found them loose and corroding. I cleaned them all off using dermal wire brush a little Dielectric grease. I then went through black water sensor wires. found wires loose. They worked well for the rest of the season. I also went through all the grounds I could find. Shaking my head at all the loose grounds I found that started to corrode. Esp. the generator ground.
BDenn is online now   Reply With Quote
Reply

Tags
black, black water, tank, water, water tank

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 08:16 PM.