Key Points:
- Poop and toilet paper can cake onto the sensors causing the level monitor to read full when it’s actually low or even empty.
- To fix misreading sensor issues, follow the step-by-step instructions in our guide on How to Clean and Restore RV Holding Tank Sensors.
- If multiple treatments using Restore-It sensor cleaner doesn't restore your sensors, they may just be broken and need to be replaced.
Within the RV community, misreading black water holding tank sensors are known for being one of the most frustrating issues anyone can run into! It can sometimes seem like you’ve tried everything under the sun to restore your sensors, and they still won’t read correctly. It might read full only a few days after dumping, and unless you have a LOT of people using the RV facilities, you shouldn’t have a full tank that soon after dumping. Contrary to what you might initially think, it’s actually pretty simple and easy to completely restore your black tank sensors. In this article, we’ll briefly describe why black sensors may be misreading and provide some resources on how to easily restore them to proper functionality.
Why Are Your Sensors Malfunctioning?
Sensors malfunction for only two reasons:
- Something is covering the sensor. If something is covering the sensor three quarters of the way to the top of the tank (even a thin film of dried waste), the monitor will always read three quarters full even right after you have dumped.
- Sensors are broken. If your sensors are simply broken, it could read full, empty or anything in between; it may not show any readings at all.
Two things can cover the black water sensors:
- Solid human waste (or a liquefied version of it)
- Toilet paper
Sensors are famously unreliable because they are pretty cheaply made, so it is possible that they can easily break altogether, but if you are not practicing proper tank care habits and using high-quality products, sensors that are usually working can get dirty and misread. If you want more information on how the sensors work and the pros and cons of popular cleaning techniques/products, refer to the Why Are My RV Sensors Not Working? guide. In the next section, we’ll provide you with the resources to clean your black water sensors so they read correctly.
Cleaning and Restoring Black Tank Sensors
Cleaning built-up waste from your black water sensors is very easy, and we recommend using Restore-It to do this because the blend of bacteria strains and enzymes in this product are the toughest on debris that clings to sensors. If you didn’t know, the bacteria in Sensor Cleaner is a type of bacteria that doesn’t add to existing odors and actually eats away at the film on the sensors just like a sucker fish eats algae off fish tank walls. It’s an easy process that we describe step by step in our guide on How to Clean and Restore RV Holding Tank Sensors. Obviously cleaning sensors while full-time RVing is a little trickier, but we have some modifications for full-time RVers spelled out in the guide mentioned above.
In the majority of cases, our easy-to-follow steps will clean the sensors on the first try. There may be situations where you’ll need to apply another sensor treatment because years of built-up waste can be pretty tough to break up. After 2-3 cleanings without seeing any improvement in sensor readings, it’s possible your sensors are simply broken and need to be repaired.
Misreading Sensors? We Can Help!
Misreading tank sensors are very common and in most cases pretty simple to fix! We’ve helped thousands of RVers restore their misreading sensors in their RV black and gray tanks, and this Field Guide (our free downloadable PDF) is going to help you!
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