Do you know? RVs hold water in two types of tanks: Gray water tank and Black water tank.
As the name suggests, a gray water tank holds water from the kitchen sink or bathroom sink after use. Similarly, black water holds water containing debris from toilets, hence the name.
Cleaning the gray water tank is simple and easy. However, when it comes to black water cleaning, there are a variety of steps involved.
What if you’re done dumping the black water tank, but it still shows the tank’s somewhat full? It means the sensor on the black water tank is malfunctioning.
I’ve discussed everything you need to know about RV black water sensor cleaning down below.
What is an RV Black Water Sensor? How Does it Work?
RV black water sensor shows the approximate quantity of water in the tank. The sensor comes with three metal nubs, which connects to LED light blinkers. These blinkers turn on to indicate the water level when it touches it.
The indicators usually show the water level up to one third, half, and three-fourth of the tank.
What Causes a Black Water Sensor to Malfunction?
There are usually two reasons a black water sensor malfunctions:
- Firstly, the sensor in the tank could be broken. It’s relatively common for the sensor to break down. In such a situation, nothing you do to clean the tank would matter. You need to replace the sensor with a new one.
- Secondly, the sensor can malfunction and show incorrect readings, if something is stuck on the sensor. It causes the metal nub to indicate the filling of the tank to a certain level.
We know the black water tank holds the waste from the toilet, which includes liquid as well as solid waste. If the sensor shows a wrong reading, it means either a wet tissue or wet debris is stuck on the feeler.
How Do We Know if The Reading Is Wrong?
Generally, two ways indicate the sensor is malfunctioning.
1st Method: When the LED indicator is showing two-third or half full water level, while the blinker below it is off, it means a tank can’t be two-third full if it isn’t half full, thus indicating the sensor’s malfunctioning.
2nd Method: If you’ve just dumped your black water tank, but it still indicates the water level up to some limit. It’s a clear sign of a faulty sensor.
What to Do if a Black Water Sensor is Showing Wrong Readings?
I would recommend you to follow the techniques discussed below to clean your black water tank and the sensor. However, if nothing works, I’d recommend you to get it checked and replaced if it’s broken.
All about RV Black Water Sensor Cleaning
There are a variety of ways to clean your RV’s black water tank and its sensor. However, these three are the most effective, and RVers swear by these.
Using Ice Cubes and Dishwashing Detergent
For this method, you need to dump half a cup of dishwashing detergent either in liquid or powdered form in the toilet. Take a bag of ice and drop it through the bathroom as well.
Make sure you use detergent specific for dishwater use. Using a regular dishwashing liquid soap can cause a messy episode full of bubbles.
After pouring the detergent and ice in the toilet to reach the black water tank, you need to go on a drive. You can drive for half an hour or until you reach your next destination.
The ice and detergent mixture thrashes along the inner walls of the black water tank, while you drive. It causes the debris stuck on the walls to loosen up and ultimately mix in the liquid.
Afterward, dump your tank water in a dump station, fill your tank with clean water and dump again. Repeat the process until it runs clear.
Tank Cleaning Wand
The procedure involves use of a tank cleaning wand, easily available online. Buy a quality product for this purpose.
You need to drag a hose from the window or RV door to the toilet, attach your tank cleaning wand to it at one end. Feed the wand through the toilet into the black water tank.
After you feel you’ve reached into the tank enough, open water connects. The wand’s design allows it to spray water sideways instead of one direction only. The sideway spray with full pressure cleans the tank.
Make sure the tank’s valve is open, so you know when the water runs clear. After you’re done with the cleaning, take out the wand after some time with immense care.
It’s better to wear gloves, glasses and keep your mouth closed, as the wand may drip a little after it comes out of the reservoir. You don’t want any of that water on you.
RhinoFLEX Rhino Blaster with Gate Valve
Many RVers don’t like the idea of handling a wand that’s been to almost a sewer type reservoir. Moreover, the dragging of this cleaning wand along with the hose through their RV turns them off.
In such a situation, you can invest in a RhinoFLEX Rhino Blaster with Gate Valve. The product allows you to connect it to your RV’s septic from the outside.
You can fill in your tank through the hose attachment on the rhino-blaster. Rinse it and then dump it. This particular product comes with a gate valve, which makes the direction of the flow easy for you to control. You can flood the tank from outside as well as dump it.
Moreover, when you close the gate while filling in the tank, the water stays there until you open the valve and let it out. Without the valve, there is no point in shooting water in the tank that’s coming out at the same time.
Using Bleach/ Chlorine with Water
Another way to clean the RV black water tank and its sensor is by using bleach with water. For this method, you need to use half a cup of bleach, pour it in the toilet and flush so it reaches the black water tank.
Make sure the tank is half full. Let it sit for some time. Drive around for five minutes or so. The movement would allow the solution to splash and clean the inner walls. It kills the odor and cleans the tank thoroughly.
After the drive, immediately dump the water with bleach or chlorine solution. Fill in the tank and flush it with clean water. Dump the water after rinsing.
Repeat the rinsing process twice or thrice.
Concerns Involving the Use of Bleach Solution
Many RVers despite using bleach or chlorine solution to clean their black water tanks. Bleach can cause the rubber holdings to warp.
It’s true if you don’t follow the proper procedure and thoroughly rinse your black water tank with clean water twice or thrice, there could be some residue.
Bleach is harsh and can cause your rubber holdings to warp in a months’ time. As a result the water may start dripping. Moreover the product’s life is compromised.
Thus, clean your tank with bleach or chlorine solution only if you can follow the protocol. Rinse it thoroughly and then be on your way.
The Ideal Way, I Recommend
If you follow the above-mentioned ways to clean your RV back water tank, I’m sure you would get the desired results.
However, if you don’t find the sensor working after following one of the ways, I recommend you to follow all three ways in the same pattern I’ve mentioned.
It involves adding a dishwasher detergent with ice cubes though the toilet, into the black water tank. Going on a drive, afterward dump the tank water. Rinse it by filling through a hose, pouring buckets or using a rhino blaster with a gate valve.
Then, pour bleach solution through the toilet. Let it sit for a maximum of five to ten minutes, drive around to splash the solution in the tank. It would kill the odor and germs in the tank.
Lastly, rinse your tank by filling it fully with clean water twice or thrice. The whole procedure sounds like a lot of work but hey, it promises results.
Check your sensor after dumping the black and I’m sure it would be working fine. If you still find the sensor malfunctioning, I would recommend you to get it checked and replaced.
Few Tips to Follow
Here are a few tips to maintain your black water tanks and its sensors.
- I would recommend you to clean your tank every time you dump the black water. It doesn’t allow any debris to form on the walls.
- Invest in a good holding tank treatment to avoid any residue build up.
- Invest in a clear elbow that connects to the septic hose. So, you don’t have to drag the hose through your RV’s window or door,
- A clear elbow with water hose attachment allows you to see if the water is clear or still dirty as well.
- Even if you have a dump station facility on a campground, I would recommend you to keep your dump valves closed unless you plan to dump.
- If the valves are open, all the liquid would flow through leaving the solids behind, which can lead to an even bigger mess. Let the bacteria in the liquid break down the solid, so when you dump it, the process is relatively hassle-free.
There is no better thing than maintaining your RV’s black tank on a routine basis. A thorough cleaning now and then would not only maintain your RV’s black tank but also kill any foul odor to build up.
If the tank is clean, there is less chance of a black water sensor’s malfunctioning. However, if it happens, you know the right way to clean your sensor and the tank.