holding tank emptyied shows as 2/3 full

[karen123k]

I realize movement helps break everything down. what if u are living in and not mobile? how do u dissolve it? I am using a chemical. I dumped my tank but I don't think it worked sensors says the same as before.

[MTPockets1]

My black tank sensors are 100% reliable.. Three years now full time and I can rely on all the lights being on full every time I dump. It's pretty amazing these little lights all still work all the time. LOL.

[RustyJC]

Our new DRV came with the non-contacting sensors that read through the wall of the tank. So far, they seem to be working fine. On our previous 5th wheels with the tank probes, I finally gave up on trying to keep them clean and working - it's a lost cause, as far as I was concerned.

Rusty

[C-Bears]

The sensors quit on my last two fivers. My fresh water one work good and I do check it once and awhile. I could care less about the black and two grays working.

There are after market sensors that work pretty good but IMHO they are a waste of money.

[stickdog]

If I run the black tank flush after dumping the empty light and the full light will be on and the 1/3 and 2/3 lights will be off. I always wonder how the top of the tank can be full and the bottom empty???

[time2roll]

No Fuss Flush tank rinser with custom spray pattern works perfect on mine.
Besides it is the FULL indicator that matters and you should know approximately the number of days to get full.

[Escargot]

Karen,

My tank level sensors are accurate the majority of the time. The black tank sensor misreads on occasion and when it does I use
this to clean the tank sensors of any gunk that may have accumulated.

[mrw8i]

It doesn't take much to make the black tank sensor read incorrectly. There is something stuck between the sensors (toilet paper, sludge, or other nice things) which stay moist, even when the tank is empty, thus creating an electrical connection between the sensors.

You can install after market sensors that claim to never have this problem.

You can get a wand that you put down inside the toilet and do a pretty good job of cleaning the side walls of the tank.

You can ignore it, knowing your tank is empty.

[bob_nestor]

The consensus here seems to be that sensors, especially those on black tanks, are pretty much worthless. Not necessarily disagreeing with that, but I have been able to keep mine more or less working by using Digest-It in the tank a couple times a year. I usually empty the tanks first, then toss in a cup of Digest-It and enough water to bring it above the faulty sensor. In my case it's usually the 2/3 full one. Normally when I do this it's after returning from a camping trip so it sits in the tank until my next outing. I then dump it when I reach my destination, so the travel sloshes the liquified******around in the tank.

I have noticed with the sensors that they can be very sensitive. I can dump my tanks and have them read zero, but on the trip home (about 10 miles), the sloshing of the small amount of remaining liquid can cause them to read 1/3 full when I get home. After an hour or so they drop back to zero though.

Digest-It

[Road_Runners]

When I first started RV camping I really tried to make those holding tank lights work. Finally gave up. With experience, we have learned when it is time to dump.

[greende]

I started RVing before sensors. I find that I rarely if ever look at them.

[CA_Traveler]

Those monitors have only one purpose - for the salesman to explain how the rig has a great tank monitor system. Right up there with the 4 light battery monitor.

[Veebyes]

Dick_B wrote:
We generally ignore our Black Tank reading and dump every week regardless of what it shows.

Thats about it.

[Dick_B]

We generally ignore our Black Tank reading and dump every week regardless of what it shows.

[downtheroad]

Don't know if you are new at this RV thing, but pretty much forget the sensors...

Also, even more important....DON'T leave the drain valve open 24/7 on your black tank. Use lots of water and only drain it when it is at least 2/3rds full.

[phillyg]

Tank sensors are notoriously inaccurate; I don't rely on them at all. Unless you're very wasteful with water I doubt you'd need to dump more than every three days, if that.