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*This is a guest post by Michael Scarpignato of RV Blogger
When your RV black water tank sensor isn’t working, it can be a very frustrating and worrisome situation. You’ll know there’s a problem if the sensors show your tank is full, or partially full, after you dump.
How will you know if your black water tank is really full or not?
It may be time for an RV black water tank cleaning.
This situation usually occurs because the sensor in the tank gets gummed up and malfunctions. This is why regularly cleaning your RV black water tank is so important. But every now and then it happens, and it may be time for an RV black water tank sensor cleaning.
Let’s take a look at how the sensors work to better understand how to prevent a sensor malfunction in your RV black water tank.
And we can also look at how to maintain and do a thorough RV black water tank cleaning.
Table of Contents
How Do RV Black Water Tank Sensors Work?
RV black water tank sensors are little metal nubs that are screwed in the sidewall of the tank. When water inside the tank hits the metal nub, it completes the electrical circuit and turns on the colored lights located in your RV monitoring panel.
The black water tank sensors are placed at equal intervals in the black water tank like 1/3, 2/3, and Full.
Sometimes, debris gets caught or builds up on the end of a sensor inside the RV black water tank. The debris is wet, and it completes the circuit even though the tank is empty. So when you look at your control panel, one of the fill level lights will be on even though the tank is empty.
There are two ways to deal with this problem: routine maintenance and a good RV black water tank cleaning.
But before we dive into maintaining and cleaning your RV black water tanks, there is one critical factor to consider: toilet paper.
You need to use toilet paper that is made for RVs, or you will have lots of problems.
This RV toilet paper is designed to break down faster and more completely. That way, it will not build up or get stuck to the tank sensors.
Routine maintenance to prevent constant RV black water tank cleaning
The best way to prevent faulty black water tank sensor readings and to constantly have to do a complete RV black water tank cleaning is to flush your RV holding tank regularly and use a good tank treatment. We like to flush our black water tanks almost every time we dump.
To flush your tanks, just fill them with fresh water after you dump and then drain them until there is no debris and the water runs clear.
The best way to do this is to make sure you have a clear elbow for your septic hose so you can see what’s going on. Then after each dump, just fill the black water tank with fresh water and dump again.
Doing this each time you dump should keep debris from forming in the black water tank or on the sensors.
You can fill the RV black water tank by running the toilet or dumping buckets of water down the toilet until the tank is full. It’s a bit of a slow process.
Or, you can pull a hose through the window and run water into the toilet until the tank is full. But the most convenient way is to buy a sewer elbow with a water hose attachment and fill the tank from outside the RV. We have one, and it’s very convenient!
But, even though you rinse the tank after each use, every once in a while you need to do a more thorough RV black water tank cleaning.
There are three fundamental ways to clean your RV’s black water tank.
1. Use Dishwashing Detergent and Ice Cubes
2. Use a Tank Cleaning Wand
3. Use Chlorine and Water
How to do a thorough RV black water tank cleaning
1. Use Dishwashing Detergent and Ice Cubes and Drive Around
This is a great method for RV black water tank cleaning. Be sure the tank valve is closed, and then fill it about 1/2 way with water. Add 1/2 cup of dishwashing detergent as you would add to a dishwasher. Do not use dishwashing liquid because you don’t want to make a bunch of bubbles.
If you have some ice dump it down the toilet, so the cubes go into the black water tank. Then go for a drive or drive to your next destination. You can let the solution sit in your tank for up to 24 hours after you drive. Once you are ready, empty the tank and fill it with clean water and dump it again.
2. Use an RV Black Water Tank Cleaning Wand
This is the most direct way to do a complete RV black water tank cleaning. Just bring a garden hose through a window and attach the RV cleaning wand. Then lower the wand through the toilet and spray the inside of the black tank.
The wand is made to spray water sideways rather than straight, so it will clean the sides of the tank very well. Leave the black tank valve open while doing this and keep spraying until the water runs clear with no debris.
3. Use Chlorine and Water
There are a lot of people who disagree with adding chlorine to the RV black water tank because they fear that the chlorine can damage some rubber plumbing parts. And they are correct. Too much chlorine causes rubber to become deformed, which means that any rubber seals may fail.
This is most evident in the toilet tank of a regular toilet in your house.
If you were to use a toilet tank cleaner that contains chlorine, like the puck-shaped cleaners you just drop into the toilet tank, the rubber seal that keeps the water in the tank between flushes will warp and cause the tank to “run on.”
The reason this happens is because the puck is full of chlorine. And rubber sitting in water with a high concentration of chlorine will warp in as little as a month, and the seal will fail.
But if done correctly this method will help to disinfect the tanks from any odor-causing bacteria, and it will not harm your rubber seals.
Here is the proper way to sanitize your RV black water tank:
Start by dumping the RV black water tank and then fill it to 2/3 full of water. Then add a cup of bleach to the RV holding tank by dumping the bleach down the toilet. Then fill the tank until it’s full. Once the tank is full wait 5 minutes and then drain it completely.
Fill the tank with fresh water and dump it again to make sure you get rid of all of the chlorine in the holding tank.
Actually, the very best way to superwash your holding tank is to perform all three methods above one after the other.
If done in order, you will agitate and soak the tank in dishwasher detergent, then hose down the inside of the tank with a pressure wand and finally disinfect the tank with a chlorine solution and rinse it out thoroughly.
This way, you’ll know you did a complete and through RV black water tank cleaning and your sensors will work perfectly, too.
Conclusion on RV black water tank cleaning
Now you know how to clean your RV black water tank and sensors so they are clean and functioning properly!
And you know that the best way to prevent future problems is proper care and maintenance today. With your RV sensors is in good shape you can be ready to take on your next adventure worry-free.
About the author:
Mike and Susan of RVBlogger.com are avid RVers who love traveling, sightseeing and camping in their RV. In true Maryland fashion, they named their RV Chessie, since they live close to the Chesapeake Bay! Although Mike is a full-time RV blogger, they are part-time RVers. They have RV’d all over the US and Canada and just can’t get enough.
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