The Best RV Holding Tank Sensors for 2023

One of the most annoying things about RVing, especially for boondockers, is figuring out how much stuff lies inside your holding tanks. Holding tank sensors are supposed to make this task easy, but many are unreliable and provide false readings.

This article will help alleviate these issues by showing you how to find the best RV holding tank sensors.

I’ll guide you through the entire buying process with discussions on various essential topics. To be specific, I’ll talk about determining buying factors, how these sensors work, how to clean them, and much more. Each of these discussions will make finding suitable ones for your particular purposes much more manageable.

You’ll even have an excellent starting point with in-depth reviews of my five favorite options. As a result, you may end up learning more about these devices than you ever thought possible.

Let’s now get this process started and find your perfect RV holding tank sensors. I promise reading this article will do nothing but make your life much easier.

6 Top-Rated Holding Tank Sensor for RV Reviews

This section will contain reviews of six high-quality RV holding tank sensors. Each of these discussions should offer you a better understanding of what these devices can provide an RV owner. It’ll help make separating the low-tier choices from the best options a simple endeavor.

1. RecPro RV Water Tank Probe Sensors

If you’re looking for a simple solution, RecPro’s RV Water Tank Probe Sensors should be near the top of your consideration list. These sensors offer a straightforward construction while providing outstanding results.

You can expect these results to last a long time, as well. These sensors are made up of stainless steel and vulcanized rubber grommets to ensure top-flight durability. Plus, their rust-resistant hardware will do an excellent job keeping them in good shape within the harshest environments.

I can’t see anyone lucky enough to buy these sensors replacing them anytime soon. Multiple buyers attested to their durability in this product’s customer reviews. These types of reports are what any buyer wants to see when researching these devices.

The sensors’ screw-in design was another top-tier feature. Honestly, I didn’t find any trouble installing them into my RV black water tank design, which is a miracle. My ability to do these sorts of tasks isn’t worth bragging about: newbie RVers won’t even have issues with it.

I was also pleased with these sensors’ multi-purpose abilities. You can utilize these devices in freshwater tanks, gray water tanks, and black water tanks system without issues. It makes their versatility rather impressive when compared with most other holding tank sensors available.

This option coming in a set of six wasn’t too shabby, either. I only required four for my needs, but now I have a few backups when one of the other sensors becomes unusable. It helps make sure I don’t have to spend more money on these devices anytime soon.

Moreover, the price tag on these six sensors is unbelievable. It’s a bargain that shouldn’t be overlooked by anyone looking to buy these products. Honestly, finding a better deal for sensors of this quality would be a hard thing to do.

2. Valterra T21301VP RV Horst Miracle Probes

Valterra’s T21301VP RV Horst Miracle Probes is a perfect solution for people who keep getting false readings from their black tank sensors. These products are designed specifically for dealing with the environments that lie inside a black water tank.

For instance, these sensors have a specially designed roof to ensure accurate readings. Valterra put it into their designs to stop toilet paper from being a common nuisance. This attribute was one that several buyers made a point to praise in their customer reviews.

I was thrilled about the “roof” feature, too, but I’m more impressed by these sensors’ versatility. These products can fit into all ⅜-inch diameter holes and compatible with most existing monitors/wiring diagrams.

Most RV owners shouldn’t have any trouble installing them right into where their old sensors were located. It’s an ability that makes this entire process less taxing and time-consuming than with other holding tank sensors.

I found myself loving this product’s rather long construction, as well. This design can easily prevent buildups of sludge or other residues from causing false readings. It makes the entire sensor a much more effective and durable piece of equipment.

Valterra also provides buyers with a choice about whether they want gray water tank sensors or black water tank sensors. As a result, it becomes easier and more convenient to choose a set of four based on your particular needs.

But I wasn’t too thrilled with this option’s price tag. It’s a bit higher than I’d typically expect for a set of four RV holding tank sensors. Buyers will have to decide whether its superior performance ability and unique features are worth this increased price tag.

In my case, I find these qualities worth paying these few extra dollars. Valterra did an excellent job building sensors capable of meeting all my needs when it comes to these devices.

3. RecPro Miracle RV Holding Tank Sensors

The RecPro Miracle RV Holding Tank Sensors have become a favorite among rig owners for a number of different reasons. But I’d have to imagine that most of them are such happy customers because of the excellent design.

What makes this design such a hit? Well, these sensors feature an extended sensory pin and hood to ensure false readings are a thing of the past. You can actually expect this hood feature to prevent almost all pieces of residue from getting stuck onto the sensor.

The extended sensory pin is crucial because it allows these sensors to get a more accurate and complete reading of a tank’s liquid level. An RV owner can expect the right information to be coming from their holding tanks whenever utilizing these sensors.

Aside from these stellar design features, I was also thrilled by the stainless steel head. It should have no trouble providing excellent durability and long-term use. I would expect these sensors to last more than a few years with this top-tier design.

The included directions were another massive highlight for me. In most cases, any instructions that come with these devices are entirely unreadable. But these made installing the sensors a relatively uneventful and straightforward task.

Some other notable features include being a set of four, ⅜-inch diameter, black water tank usage, and excellent customer service. Each of these aspects only further conveys this option’s overall convenience.

4. Full Spectrum Parts ‎T21302 RV Water Tank Level Sensors

Our next option, Full Spectrum Parts ‎T21302 RV Water Tank Level Sensor, is an intriguing set of devices for freshwater or gray holding tanks. Honestly, it was difficult not to be impressed by how well they worked after installing them.

Each RV tank level sensor had no issues providing accurate readings, which many options struggle to do.

I would have to attribute this successful performance to their rather intriguing design. These sensors were made with an uncovered end piece to ensure they were highly sensitive. So far, I don’t have any complaints as this design only seems to make them effective.

The installation process wasn’t overly complex, either. Full Spectrum Parts ensured these sensors were compatible with existing wiring for Horst Miracle Probes. So I didn’t have to do severe rewiring or complicated maneuvering to make them work.

Another appealing aspect was the variety of buying options. Each buyer will have a choice between five quantities, ranging from two sensors to ten sensors. I only needed to replace the old probes in my gray water tank, so I chose the 4-pack.

It also helps that this 4-pack wasn’t overly expensive compared to other options. I would even go as far as calling it a bargain. I was tempted to purchase a 10-pack to ensure I had replacement sensors if one of mine failed again.

5. LevelGuard Z25302RK Monitoring System

RV owners looking to replace their entire tank monitoring system should seriously consider LevelGuard’s Z25302RK 200 RV 2-Tank Monitoring System. After all, it’s capable of providing accurate, reliable readings of two tanks simultaneously.

One of the reasons for its effective results is its sensor placement. This monitoring system has sensors that attach to the tank’s exterior rather than the interior. As a result, it becomes unaffected by buildups of toilet paper and other residues.

This placement encourages better readings by merely addressing the issue, causing many other sensors problems.

It also doesn’t hurt that these sensors are attached with a highly effective adhesive that can withstand vibration and moisture without issue. As you can imagine, this aspect alone has made the monitoring system a real godsend for many rig owners.

I was overly pleased with this option’s included LED display, as well. It made reading the holding tank information absolute ease from even considerable distances. I don’t have the best eyesight, either, which means most people shouldn’t have any issues.

More importantly, this option doesn’t make monitoring these tanks difficult and keeps it simple. It follows the standard four-level system of empty, ⅓, ⅔, and full to ensure easy usage. I doubt anyone will have trouble figuring out where their holding tanks stand with this system in place.

You also can’t overlook this option’s multi-purpose abilities. It’s usable with any volume tank and doesn’t discriminate when it comes to what water-based solutions suit its capabilities. Users can monitor industrial liquids, farm liquids, sewage, wastewater, fertilizers, and many other applications.

6. RecPro RV Tank Monitoring System

Our final option, RecPro’s RV Tank Monitoring System, is another monitoring system that’s capable of making your holding tank dumping process much easier. This option has several essential features to ensure it can meet most RV owners’ expectations.

A favorite of mine would have to be its reliable, durable sensor probes. These probes contain a construction you’d expect from any high-quality sensor out there. Each of them has a stainless steel head, sturdy rubber base, and hardware with rust-resistant capabilities.

Thanks to this, these sensors shouldn’t have any issues providing accurate readings. You can then read this information on the system’s straightforward monitor. These aspects together make the entire using process a breeze for users.

Installing the monitoring system is made much easier by RecPro providing everything needed for the assembly. Customers will get sensor wiring and helpful installation instructions with their purchase to help the process go more smoothly.

I was thrilled to see this product came in two different colors, as well. It might not seem like a big deal, but I always prefer when I get a choice regarding style or color scheme. In this case, I would have to go with the black option over the white as it suits my rig much better.

Buyers will also benefit from this system’s ability to control heaters and water pumps. There’s a red button on the monitor that allows users to shift these devices on and off. It’s an extra level of convenience, which most other similar products don’t offer.

Holding Tank Sensor for RV Buyer’s Guide

Finding effective RV holding tank sensors can be a little more complicated than a rig owner might expect. I’ll discuss several factors below, which should break this entire process down into a more manageable task.

• Construction Material

RV owners should first look at each sensor’s construction material when considering these products. You’ll need options made from durable components to promote top-tier effectiveness and tank readings.

I’d recommend looking for sensors made from stainless steel and such. It should give them rust-resistant qualities and high levels of durability. After all, you don’t want to be doing this entire process again anytime soon.

Moreover, look for options with constructions designed to prevent common issues. An excellent example would be a sensor having features to stop toilet paper or other residue buildups from affecting their readings.

You should also take a look at each option’s customer reviews. These resources should provide some in-depth analysis of the product’s overall longevity. Honestly, I’d imagine the more negative ones will be more useful than the positive write-ups.

If there’s a durability issue, these negative reviews will be vocal about it. RV owners don’t hold back when a product doesn’t meet their overall expectations. It’d be wise to use their horrible experiences with specific options to your advantage.

It’s a simple and effective way to ensure you don’t become the person writing a negative review. This experience is something that we’d all like to avoid.

• Easy to Install

Your RV holding tank sensors shouldn’t be overly complicated to install. In most cases, these products feature a simple screw-in process that doesn’t take much time or effort. But some manufacturers make this process more complicated than necessary.

Rig owners would be smart to avoid them by researching the installation processes beforehand. In other words, read through the sensor’s product description or manual to ensure you feel comfortable doing it yourself.

This action will prevent anyone from buying sensors that aren’t user-friendly to their particular preferences. As a result, you won’t end up wasting money on products, which make your life a nightmare when installing them.

It’s also essential to account for the sensor’s size concerning their installation. You’re going to want options that can directly replace your old ones. Otherwise, your chosen options might not fit into the previous RV holding tank sensor wiring diagram and become a huge hassle.

• Brand

Buying from a trusted and reputable RV holding tank sensor manufacturer is a must. It’s the only way to make sure these products meet your needs and provide reliable tank readings. However, finding these manufacturers can be a little challenging.

Over the years, many companies have tried their hands at making these products. It has led to many subpar quality RV black tank sensors and gray tank sensors on today’s market. But how does a rig owner separate these low-tier brands from the high-quality ones?

It’s another area where other customers’ reviews and experiences will be crucial. I’d suggest talking with other RV owners who’ve bought sensors in the past. They should give you a better idea about what brand creates effective options and what one doesn’t.

Plus, I’ve given you a head start by introducing some top-tier brands in our product review section. Each of these companies has a long-standing reputation for making excellent tank sensors that rig owners love.

If you stick with these brands, I’m more than confident that your chosen holding tank sensors will be everything you’ve imagined.

• Quality

Of course, none of these other factors matter much when a sensor doesn’t provide optimal results. You must do extensive research into each option’s ability to provide accurate readings and avoid problematic issues.

Buyers would be doing themselves a favor by choosing a model with proven rust-resistant capabilities. As I mentioned earlier, this feature will help promote longevity by preventing corrosion or rust from ever becoming an issue.

It’d also be smart to look into options with features designed to stop buildups of grime, toilet paper, and other nuisances. The “roof” addition to Valterra’s T21301VP Horst Miracle Probe would be a prime example.

But it’s essential to make sure these features are useful. Many manufacturers will use certain buzzwords as selling points without them offering actual effective results. I’m starting to feel like a record that’s skipping, but your fellow customers’ reviews will be valuable in determining each option’s overall quality.

I’d recommend checking out some RVing forums, as well. These sites often have useful discussions about these sorts of products, debating the best available options. I can’t begin to describe how much these resources have helped me in the past.

• Type

Some RV holding tank sensors are explicitly built for being black tank sensors or gray tank sensors. Meanwhile, others will work in both situations without any issues. It’s worth noting that most single-purpose options will cost a bit more than the multi-purpose counterparts.

As a result, it’s essential to figure out what type of option you’re looking for before starting the search. This action will help limit your number of choices down to a more manageable number. It’ll make the entire process a much easier and less stressful task.

I’d advise buying options made for both situations, as these sensors tend to be more versatile than their counterparts. Their added versatility seems to promote more longevity and effectiveness, which is what we all want in these products.

More importantly, their lower price tags are absolute bargains when choosing high-quality options. The reduction in initial cost could even make up for having to potentially replace them sooner than single-purpose ones.

• Quantity

These sensors will come in multiple quantities, but mostly in sets of four. Each RV owner will have to decide how many would be best for their needs. Honestly, I’m always going to recommend getting an extra sensor or two when buying these products.

It’s an easy way to prepare for one of them becoming defective in the future. Therefore, you won’t have to buy more sensors but can simply install your extra one. It becomes a cost-effective move that can save you the hassle of doing this entire process again.

• Price

The price will play a factor in buying any type of product. The best RV holding tank sensors aren’t any different as these products are available at several cost levels. Due to this, each buyer should build a budget around their particular needs and required features.

For instance, a person who’s looking for a new entire RV holding tank monitoring system will need a much higher budget than someone buying a few sensors. Accounting for these details ensures your budget ends up being a useful and usable resource.

You can then utilize this resource to make this process a lot more straightforward. It’ll break down the number of choices into only options that meet your particular requirements. Trust me; it’ll make your life easier when choosing your new RV holding tank sensors.

RV Holding Tank Sensor FAQs

This FAQ section will cover a few essential topics that our buying guide and reviews didn’t discuss in enough detail. In other words, these discussions should answer any remaining questions running around inside your mind.

How do holding tank sensors for RVs work?

Understanding how RV holding tank sensors work is a vital piece in choosing high-quality options. These devices are mounted through a holding tank’s sidewall, which allows their heads to be on the tank’s inside.

You can then expect them to be lined up in a line on your holding tank’s body. Most tanks will provide readings at four distinct points: empty, ⅓ full, ⅔ full, and full. These readings come from the sensor being grounded at these junctures when the waste rises past them.

For instance, an RV black water tank sensor would indicate ⅓ full when a tank’s waste hasn’t made it past the ⅔ sensor. This reading comes from the waste electrically grounding these sensors as the tank fills.

In response, their respective indicator lights will light up on the monitor panel as the waste passes each sensor. It’s not the most complicated process ever, but it does its job when these sensors work effectively.

But many rig owners experience false readings with low-quality models because of how these products are designed. These sensors work by completing the circuit within your holding tank’s system.

As a result, certain contents can complete this circuit by connecting the sensor heads within your tank like toilet paper. This situation can cause incorrect readings and make your life a lot more annoying on the road.

Certain manufacturers have adjusted for this issue by creating sensors, which attach to your holding tank’s exterior. Thus, toilet paper buildups between the sensor heads become a non-issue, and usable readings become commonplace.

How accurate are RV tank sensors?

The accuracy of RV gray or black water tank sensors can vary significantly. However, in most cases, the devices are relatively accurate.

An option like RecPro’s Miracle RV Holding Tank Sensors or Monitor Kit with probeless adhesive sensors will have no trouble offering accurate readings. These sensors will ensure any RVer who buys them feels satisfied with their purchase.

Why does my black tank show full when empty?

Black tanks are notorious for getting toilet paper build-ups and waste stuck on their sidewalls. It’s often caused by RVers using restroom paper not meant for rig plumbing systems. This paper doesn’t break down and gets stuck, causing RV holding tank monitor sensors to display a “full” reading.

Such a problem is common for marine holding tank monitor sensors, as well. So boaters and RVers need to be extra cautious about their toiletries.

I’d recommend cleaning out the holding tank thoroughly to remove any blockages. Once done, these sensors should return to offering accurate readings.

How do you calibrate RV tank sensors?

Calibrating RV tank sensors is essential to ensuring they provide accurate readings. It’s a process done by inspecting your sensor regularly. Look for corrosion, damage, or other issues that could be affecting the performance of your RV tank monitoring system.

If you do notice issues, invest some money in an RV tank sensor upgrade. You should notice the readings stabilizing after the new sensors are installed.

Aside from the above, you can do the following steps to calibrate your monitor:

• Turn the freshwater tank fill knob to “on.”
• Once water comes out of the overflow valve, that means the tank is full.
• Push the button for the freshwater tank on the monitor, and put a screwdriver into its corresponding slot.
• When turning the screwdriver to the left or right, you’ll notice the reading of the freshwater tank changing. Rotate the screwdriver while observing the indicator lights, and stop once you see they signal “full.”
• For the black and gray tank indicators, it’s better to have them signal “full” when the containers are only nearly full.

How do you wire an RV holding tank sensor?

Wiring RV holding tank sensors is a bit complicated for people who aren’t electricians. But I will walk you through the process to help make it easier. However, there isn’t any shame in calling a professional to do it for you.

If you want to attempt it yourself, start by identifying whether you have a tank monitoring setup that uses thirds or quarters. The process will change slightly based on your answer. But the good news is for both types, you can start by locating your tank sensor harness, where all the wires are connected.

It’ll either have three wires or four, depending on your setup. In any case, the harness will need replacing. Your next step is attaching the wires in this order:

For 3-sensor Setup:

• The yellow wire goes to ⅓ sensor
• The green wire goes to ⅔ sensor
• Orange wire goes to full senor

For 4-sensor setup:

• The yellow wire goes to ¼ sensor
• The green wire goes to ½ senor
• Orange wire goes to ¾ senor
• The red wire goes to the full sensor

After completing the wire connections tightly, the process should be done. Next, test RV tank sensors to see if they’re working correctly.

Where are the sensors located on an RV black tank?

The location of RV black tank sensors can change depending on your setup. However, it’ll usually be a three-sensor or four-sensor configuration.

RVers with three sensors can expect them to be on the tank’s sidewall at ⅓, ⅔, and full. But a four-sensor configuration will have sensors at ¼, ½, ¾ and full.

If you aren’t sure about whether yours uses thirds or quarters, look at your RV monitor panel. It’ll have a readable marker at all included levels.

How to install RV tank sensor probes?

Whether you’re using a KIB mp5 screw-in sensor probe or that of any other brand, the process usually involves marking the locations for the probes on the tank, drilling holes at these spots, and securing the sensors with screws.

How do you clean RV holding tank sensors?

If you’re looking to clean RV gray or black tank sensors, there are a few ways of doing it. But RV owners shouldn’t fret too much over this task as it’s pretty simple. If you follow the methods below, there shouldn’t be any problems keeping your sensors in good working condition.

Gray Tank Sensor Cleaning Method

• Close your gray tank’s valve.
• Fill up the tank with water. I’d recommend filling the water to the sensor’s highest level as a way of removing debris.
• Pour dish soap, about 20 ounces, down the sink line in your RV kitchen. This action will cause the foam to start coming from the sink and shower lines. Honestly, it’s nothing to worry about and shouldn’t be any cause of concern. You can expect the dish soap grease-eating abilities to remove any grease from the pipes.
• Keep the gray tank valve closed overnight.
• Open the valve in the morning and dump the gray tank.
• Proceed to fill and then empty your tank multiple times for rinsing purposes. Repeat the process until your gray tank’s sensor is running effectively.

Black Tank Sensor Cleaning Method

• Close your black tank’s valve.
• Fill the tank up with water. I’d suggest filling the water up to the sensor’s highest level as a more effective debris remover.
• Shake your bottle of RV tank sensor cleaner effectively.
• Use ½ of this cleaner and dump it into your black tank via the toilet.
• It’s essential to keep the valve closed for an extended period. It’s suggested to keep the cleaner in the tank for between 48 and 72 hours. As you can imagine, a rig owner gets better results when allowing the cleaner to work for a more extended period. It will enable them more extended time to remove the residue that causes those false readings.
• Open your valve and empty the tank.
• Rinse out your tank and repeat the process when/if it’s necessary.

What causes holding tank sensors for RVs to give false readings?

The main culprit of sensor problems would come from undigested waste and debris getting stuck on a sensor’s probes. If this situation occurs, you can expect a false reading indicating your tank’s full.

Most sensor probes tend to give false readings relatively easily when you aren’t keeping the solids liquefied inside your rig’s holding tanks. Due to this, keeping waste liquefied becomes vital for RV owners who want useful tank sensors.

This action will help prevent debris and solid chunks from building on your RV level gauges and sensor probes. It’s something rig owners should keep in mind when buying holding tank treatments, as well. It would be best if you always chose treatments with the ability to digest solid inside holding tanks effectively.

How to replace RV holding tank sensors?

As with most RV-related products, the installation/replacing process will differ from option to option. But most of them will have simple, straightforward instructions to make the task a breeze for even a newbie RVer. I’ll provide an example by going over how to install the Valterra T21301VP Horst Miracle Probe:

• Drain your tanks.
• Unscrew your old sensor probes from outside the holding tank.
• Screw in the new probes.
• Transfer the wires to your new sensors.

But complications can make this task a little more difficult. Some old probes might not be removable, and users will have to drill new holes into the tanks. You can then move the wires over when the new sensors are screwed into those holes.

Most of these devices won’t have installation processes much different than this one. As you can see, it’s nothing a person with limited tool-using-abilities can’t handle. But please, read the manual before doing anything to ensure you don’t miss any special instructions.

Any care and maintenance tips?

Aside from the cleaning processes mentioned above, certain maintenance tips are worth knowing to keep your holding tanks and sensors in good shape. Here’s a quick list of things every RV owner should know before going on their next trip:

• Please don’t dump your tanks until they reach about ⅔ full. This action will help keep the pressure high, which allows them to drain easier and without buildups.
• Never dump gray water tanks before dumping black water tanks.
• Make sure to flush with a lot of water whenever you dump. Some people find it useful to get a back-flush system for their black water tanks. It’s also worth noting that it’s never a bad idea to back-flush and dump a second time before leaving the dumping station.
• If your sensors are clean and still providing false readings, check to see whether toilet paper has attached the sensors. People who experience common issues with sticking should switch over to RV toilet paper. These products are designed for usage inside motorhome plumbing systems and won’t cause any problems.
• Anyone looking to store their RV should always add a couple of water gallons to their tanks beforehand. It’s also advisable to add RV-approved holding tank chemicals to the water, keeping it clean and buildup-free.

If you follow these tips, I don’t see any reason your holding tanks or sensors won’t perform at optimal rates. You should have a trouble-free plumbing system that doesn’t provide false readings or any other issues.

Where can I buy?

The best place to buy an RV fresh water tank level sensor, gray tank sensor, or black tank sensor would be on Amazon. As you might expect, their selection and prices cannot be matched by other sellers out there.

But some people don’t like shopping on Amazon for a variety of valid reasons. If you fall into this category, there are a few alternatives worth checking out. An excellent starting place would be using Camping World, which sells these sensors on its website and stores.

If you can’t find what you’re looking for at Camping World, check out Home Depot or Walmart. Both these stores/sites should have a decent selection and reasonable prices. I can’t imagine that you won’t find suitable tank sensors at either of them.

Conclusion

After reading our article, finding the best RV holding tank sensors shouldn’t be much trouble. The right choice should become relatively clear with this information now at your disposal. It’s just an exercise of using what you’ve learned during the search.

You can also feel free to use our comment section below to ask any additional questions. I’ll make sure to answer them as soon as possible. Thanks for reading!