Black Tank Level Reading 1/2 Full

[TRNewtown]

The sensor for the black tank has been reading 1/2 full even though we have dumped the tank. It's been this way for about a month now, but I'm especially concerned now since we are going to park the RV until January.
Is there anything I can do to see if the black tank is really half full, or to troubleshoot the sensor?
There has been a flow when we pull the black tank lever, but I am not sure if the tank is completely empty.

Tom
2018 Jayco Melbourne 24L

[Shokyle1]

Very common my sensor shows full. They get debris on tips. I know my tank is empty by looking down the toilet with a flash light.

[TRNewtown]

Originally Posted by Shokyle1

Very common my sensor shows full. They get debris on tips. I know my tank is empty by looking down the toilet with a flash light.

That seems like an easy way to determine if the tank is full. Thanks!

Is there a way to fix the sensor so that it reads accurately?

[eagleback]

There are two kinds of tank sensors. The ones that have failed and the ones that will fail. Ours quit working along time ago, so when the tank gets full the toilet will burp when you flush it.

[ttavasc]

We used a form of the "Geo Method" to keep the tank on our 195RB in good shape including the sensors. The following link provides some good details on this:

The Geo Method

We did this regularly and the majority of the 5 years we owned our 195RB the tank sensors worked reasonably well.

[Jagiven]

Very common issue. TP and Pooo, hang on the sensors. As long as there is moisture, it completes the circuit.

Most campers, you can look down the hole when you flush and see directly into the tank. Many people use this method to determine how full the tank really is. Depending on the plumbing in your Melbourne, you might be able to use this technique.

There are sensor alternatives. Some Uses the same style probe sensors, but the have little caps, that help prevent debris from hanging up on the probe. You can install an ultrasonic sensor. If I recall there is one, were you cut a hole in the bottom of the tank, and add clue in a "pillar". The linear sensor is inside the pillar, and it reads fluid level.

Personally, I look down the hole. But if I had a camper were that was not an option, I might consider an ultrasonic system.

I do not recall common brands, Sea Gauge is a brand people like, don't recall what style sensor they make.

After dumping I always add about 10% of tank volume of clear water back into the tank. This does two things. One, while driving, is sloshes, and can help clear the sensors. Two, it helps make sure you have enough water in the tank so you do not get the dreaded poop pyramid. Three, it helps keep odor down. If my sensors start to act up, I add about a 1/2 cup of liquid fabric softener down the tanks with the water. It changes the surface tension properties of the water, so it can soak into the "stuff" easier which helps soften it up and encourage it to fall off the tank walls and sensors.

[TRNewtown]

Originally Posted by ttavasc

We used a form of the "Geo Method" to keep the tank on our 195RB in good shape including the sensors. The following link provides some good details on this:

The Geo Method

We did this regularly and the majority of the 5 years we owned our 195RB the tank sensors worked reasonably well.

The GEO Method is worth a try: 40 oz of Pine-Sol; 4 oz of Calvin bath beads; and add enough water to fill a one gallon bottle. Add 4 oz of this mix every time I dump the tank.

Seems like a fairly simple approach, probably won't hurt anything, and is cheap.

[JFlightRisk]

snip...

Originally Posted by TRNewtown

Is there a way to fix the sensor so that it reads accurately?

We use a wand tank flusher every time we camp, 99% of the time at FHU sites. The tank is a straight shot down from the toilet. I'll flush it out while the DW watches the clear elbow fitting, and knocks on the side when the water runs clear. It's been working perfectly for 8 years now. I did have to replace the gray tank sensors this year. It was stuck on 1/3 full. I bought the Horst Miracle probes for that tank.

https://www.amazon.com/Camco-40094-S...tank+cleaning+

[Rustynuts]

Originally Posted by eagleback

There are two kinds of tank sensors. The ones that have failed and the ones that will fail. Ours quit working along time ago, so when the tank gets full the toilet will burp when you flush it.

Then there is SeeLevel gauges which always work and give you a percentage value vs a light. The SeeLevel sensors mount on the outside of the tanks and any fouling inside the tank wall does not affect them. They are easy to install (once you get to the tanks) and you can use all your existing wiring.

[travelingjw]

I stole the idea of the "Sloshinator" from someone on this site. I put 4 or 5 gallons on water along with 2 caps dawn dishwashing soap into my tank. I let it slosh around while I drive to an RV park and then empty the tank prior to setting up the TT. Has worked to clear sensors every time.