rv holding tank monitor panel not working

All the Fixes for RV Holding Tank Monitor Panel not Working


Can you imagine the horror if your RV holding tank monitor gives you the wrong reading? Your tank might get full, and you wouldn’t even know. Or the water level might be low, and you wouldn’t even be aware of it.

So, what can you do if you see the RV holding tank monitor panel not working?

Well, if you don’t know the answer, you don’t have to fear. That’s because we’re here to help you troubleshoot the faulty monitor panel. So, shall we start?

RV holding tank monitor panel not working: Solutions.

Before I begin, I want to tell you, people, that the monitor can have a number of problems. It can stop working or show wrong results.

But no matter what the problems are, we have the solutions. Hence, fear not because we’re here to guide you through it all.

Problem 1- Not seeing the light on the panel

At times, the monitor doesn’t display any light. Now, if this is true in your case then relax a bit. That’s because it’s quite normal and happens a lot.

But to make sure it isn’t wholly damaged, you need to do some tests. Firstly, you need to check the B+ wire. It’s red in color. And if it’s in the right place, you also have to check if it’s connected to the 12 VDC.

Next, you have to check if the ground wire is correctly connected or not. This wire is white in color and goes into the panel. Now, if you see anything wrong with these two wires, then be sure that you can fix it.

Solution- Fix the wire and the voltage supply issue

All you have to do is place the wires in the right place. And connect the B+ wire to the 12 VDC.

While you’re at it, also check the voltage supply with a voltmeter. If it’s the voltage, then you simply need a steady connection for the monitor to work.


Problem 2- Spotting “E” on 1 or 2 tanks

Other times, you simply see the “E” sign on the monitor for a few tanks. This happens when there is a wiring problem inside the tank.

By that, I mean that the wire for the freshwater is connected to the greywater panel and vice versa. Now, if this is the problem, then you need to work on the wires. For more information stay tuned.

Solution- Switch the wires or the circuit board

Alright, to get the annoying “E” sign off the monitor you need to switch the wires. In other words, you need to place the right wire in the right panel.

This means the freshwater wire goes in the freshwater panel, and the grey one goes in the grey panel. After you coordinate the wires, you need to reset the tank.

However, if things still don’t go back to normal, then you have to switch the printed circuit board.

Problem 3- Seeing “F” on a few tanks

Now, seeing “F” on the monitor is similar to watching “E” on the monitor. It’s simply another sign telling you that the wires got mixed up.

And that it’s urgent that you fix the wires or else the tank will keep on beeping “F.” 

Solution- Switch the wires or the circuit board

It’s time to narrow down to the solution; the problem is similar to seeing “E” on the monitor.

Hence the solution is also the same. You simply have to place the wires back into their original position. After that, you need to restart the tank, and voila!

The tank will stop showing the “F” sign.

In case it didn’t, you need to replace the printed circuit board.

Problem 4- Incorrect reading on the monitor panels

If your monitor shows false data, then there might be something wrong with the probe placement. So, how do you know that the reading is incorrect?

Well, you can empty the water tank and then check the monitor. If you see that the monitor shows that the tank is ⅓ or ⅔ full, you can be sure that the monitor is giving the wrong message.

Solution- Reinstall the probes and reset the tank

In the case of false reading, first, you have to empty the tank. This will have two benefits. Number one is you can be sure that the monitor is showing incorrect results.

Another reason is that you can check the probe placement. And if you placed it wrongly, all you have to do is pace it correctly. Later on, you need to reset the tank, and the monitor will start working again.

Problem 5- Seeing “E” on all the tanks

Sometimes, you’ll see that all the tanks show the “E” sign. That’s when you know that you have to check the wire that connects the 90 OHM sending unit and the back of the panel.

This wire is orange in color, and sometimes it’s shorted to be attached to the ground. Other times, the entire sending unit is damaged.

Solution- Install a new sending unit

As for the remedy, you need to connect the orange wire to the panel. But before working with the wire, make sure that the water tank is empty.

You don’t want the water to come in contact with the electric wires. No-no, it’ll cause a disaster, one that you must avoid at all cost.

On the other note, if the sending unit is damaged, then buy a new one and get the old one replaced.


To wrap up

See? All the problems have easy and simple solutions. All you have to do is identify your problem, and your monitor will be up and running again.

Well, folks, that’s all we have on the RV holding tank monitor panel not working. We hope you had a good read. Stay safe. Adios!

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