Grey Tank Reads Empty When Full (Reset And Clean Sensors)

Technology has created sensors to see what you cannot see. They usually work fine, unless they get dirty. Then you are blind to the levels in your holding tanks. The key is to make sure to keep those sensors clean if you want an accurate reading

It is a mistake to think that the holding tanks have a float system measuring the level of the liquid. Monitoring your tanks is done by electronic sensors and they can stop working on their own or stop working when they get dirty. Cleaning seems to be the best repair option.

To learn more about those sensors helping you see inside your holding tanks, just continue to read our article. It explores the topic so you have the answers you need. Take a few minutes to see how this information can help you.

How do I Know When my GREY Water Tank is Full?


If the sensors are not working, then you have to resort to the old-fashioned option. Just look at your sinks and showers. If they have stopped emptying, then you know your gray water tank is full.

The only problem that generally comes with a full gray water tank is either a full sink or tub. Or you might get a little flood that if not cleaned up right away will cause some major issues.

Also, you may get a little foul odor throughout your RV. That odor tells you that you need to head to the dump station as quickly as possible. if you have working sensors, just keep an eye on them as those devices will tell you when your gray tank is full.

The Grey Tank Reads Empty When Full


This is a common problem and you are not alone when it happens to you. In most cases, the sensors monitoring your gray tank simply got dirty. When that happens, the sensors send back the wrong information to the gauges on your dash or control center.

There is a possibility that you have broken wires. If that is the case, you would need to replace those wires for the sensors to start working again. Basically, when this situation arises, it tells you that you have a malfunction anywhere and it could be a treasure hunt to find the correct source.

This is why many owners do not trust their sensors and avoid reading them at any time. They find ways to self-monitor their tanks, like emptying them 2 to 3 times per week to avoid this situation.

Fixing a Grey Tank That Reads Empty When Full


There are only 2 reasons why a sensor will malfunction. The first is something is covering their little eye. This can be just about anything that enters your gray water tank.

The fix is to clean the sensor. Now you cannot open your gray water tank and do some spring cleaning. You have to put in some borax, and some dishwashing liquid and make sure the tank is at least 1/2 full. Then you go for a drive.

The second reason the sensors fail is due to a malfunction. This malfunction can be a sensor broken, wires getting loose, broke or disconnected in some way, and similar issues. This repair takes some electrical knowledge, which you may or may not have.

Try the cleaning first as the repair bill may not be that attractive.

RV Tank Sensors Always Show Empty


When you see this on your gauges, you have the two previously mentioned options to deal with. When it comes to gray water tanks, there are innumerable items that can block the sensor’s view.

This is why you need to monitor what items go into your gray water tank. Little food particles, grease, and similar items can easily coat the sensors and stop them from working.

One suggestion is to put a screen on your sinks and shower drain as well as on your washing machine drain. Keeping particles out of the gray water tank will help you avoid this problem.

There will be websites selling you their kits to help you avoid this issue but the screens work the best.

How do I Reset My RV Tank Sensors?


The first step would be to fill your freshwater tank to full. Then take a very small Phillips head screwdriver and go to your dashboard. Above the freshwater button is a tiny little screw. It is that way for this tank, gray and & black water tanks.

If your gauge is not reading full, turn the screw to the right until all the lights including the full one are lit. For the gray water tank, you can wait till it is 3/4 full. Then turn the sink tap on and wait till the full light starts to flicker. Then turn the tap off.

This will tell you that the tank is almost full. It will leave you about 2 or 3 gallons short of full but that is okay. You do not want to fill the gray water tank all the way.

How do You Clean GREY Water Tank Sensors?


The best way to do this is to put about 1/4 cup of Dawn dishwashing liquid and 1 cup of borax into the tank and add enough water to make the tank 1/2 full. Then you just go for a nice drive, letting the water mixture slosh around.

When you are done, do not forget to dump the solution so you have an empty tank while camping.

Some Final Words

You will find that at some point in time, you will encounter this situation. Usually, 9 times out of 10, the sensors are dirty. You won’t have to check for malfunctions but that 1 time can fool you so be wary and double-check everything when you have a problem.

Do the cleaning first so you can rule that option out.

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