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How to Clean RV Fresh Water Tank Sensors

Having water available on the go is a reason why RVs can be very convenient. Especially when you aren’t especially near a place to fill up your water tanks, knowing how much water you have in your RV tanks is critical.

You may already know that your water tanks have sensors. These sensors tell you how much water you have left. You can often see their levels either on your phone, on the side of the RV, or on a panel inside.

Keeping these sensors clean is important. You want an accurate reading about how much water you have left. Among the most popular ways to clean these sensors is to use water wands or soaps that you can apply to the tank. We’ll explain how each one works.

What should I do before cleaning my rv water tank sensors?

First, understand that most tanks have a few sensors. These range from full (higher up), ¾ full, half full, etc. In order to give these a good cleaning, you’ll first want to replace all the water in your tanks. This process starts with draining them completely.

Find a good place to let your water flow – in this case, the ground is likely a good option though hookups at an RV park are also good. Find the freshwater tank under the RV. Remove the safety cap from the fresh water tank. Finally, locate the stem for the freshwater tank and pull it. It will release the water. 

You can add a hose to this method if you want to avoid getting splashed. Just have the other end of the hose further away. The hose is hooked to the fresh water tank once you remove the safety cap.

Next, you’ll want to refill your tanks with fresh water using the freshwater sources at your RV park.

Use dish detergent to clean your RV tank sensors

Dish soap is the most simple method of cleaning out your RV tank sensors. You can also use RV holding tank cleaner for the same purpose, though you’ll more likely have mild dishwasher detergent available.

Note that we specifically mentioned dishwasher detergent. Not dish soap. Dish soap might be available too, but dish soap also produces large amounts of bubbles. While these are fun, they really aren’t necessary.

Pour some detergent into your fresh water tank. It’s also suggested that flushing ice cubes down your toilet might help stir the soap and rub it against sensors more.

Let this soap and water sit in the tank for a few hours. It will be difficult to tell if your sensors are in fact clean unless something noticeable happens to the sensors readings.

When done, drain the entire tank and refill it again.

Using sensor cleaner

Sensor cleaner has about the same method as using simpe dishwasher detergent. Most hardware stores and RV supply centers offer holding tank sensor cleaner.

The instructions will be on the bottle, but are more than likely involve draining your tank. You then refill the water tank with the sensor cleaner squired in. Wait a set amount of time and then drain the tank again.

Using a wand

Using a wand with freshwater is like using a pressure washer to clean your tank. Unless you have serious issues with your sensor and gunk, this probably isn’t necessary. In some RVs you might not even be able to get a wand all the way into your RV holding tank.

The wand is hooked up to a fresh water source and force sprays water into the tank. Your biggest difficulty might be seeing the sensors at this point. Otherwise, you can also thoroughly clear out your tank anyway.

You also have the option to have a professional come and clean out especially nasty sensors with a more serious pressure washer. Other options at that point might include simply replacing the sensors or tank too.

Why rinse and refill?

One of the main reasons why water tank sensors get dirty in the first place is older water. While RV sensors do age, cleaning does not necessarily prevent them from getting older. 

Since many RV users do use their fresh water tank, they can readily use the time of refilling their tank to clean the tank out anyway. This will help both for the purpose of sensors and because old water is not good for the tank.

Unfortunately, the rinse and refill itself won’t clean the sensors in your tank. While clean water will generally helps keep the sensors clean the clean water won’t do much to help dirty sensors.

Can I scrub the tank?

The answer is probably not. The tank isn’t designed for you to physically center. The dish detergent and other methods would likely be easier and more effective anyway.


Cleaning your tank is pretty simple. Most of the time, you just need time to stop and drain the tank. Adding a chemical like dish detergent or holding tank cleaner will help keep your sensors free of gunk.

Having accurate sensors is important. You won’t want to learn while out on a trip that you are running out of fresh water. Plan ahead a bit and do your sensor cleans before heading out and keep your tank clean and safe.

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