Gray and Black tank sensor issue

happy2rv wrote:
Anyone have any first hand experience with Horst "miracle" probes? They seem to get mostly good reviews on Amazon with a few claiming they are no better than the original probes. I like the idea of the see level sensors, but I'm not sure they are worth the price...

I had a customer use the Horst and was very pleased, but he later had a problem with False readings. The Horst keep the sensor from being on the side of the tank where the slime is. The minor problem I believe is from toilet paper and such. If you use RV(degradable) you should not have a problem. Doug

Anyone have any first hand experience with Horst "miracle" probes? They seem to get mostly good reviews on Amazon with a few claiming they are no better than the original probes. I like the idea of the see level sensors, but I'm not sure they are worth the price...

No products, but just read what they claim they can do and buy and install per instructions. The MAIN thing to do is, when packing up to go home and you do NOT have access at home for dumping, fill and drain the Gray and Black tanks 2 or 3 times. Then after doing this, install 1/3 tank with fresh water install the Tank chemical and this will slosh on the way home and clean the sides of the tanks. Yes, time consuming, but if you want the system to work, do what needs to be done. Doug

PS. buy and install a clear dump hose adapter so you can see the condition of the waste when flowing out. Keep filling with fresh and dumping until it flows clear.

I've put the SeeLevel the last two mh we've had and been very happy.

We had an '88 Mallard, and the sensor worked fine on that one. It used probes, and looked about like our '02 and '12 Itasca but they didn't work very well and they read in thirds which to me seemed a little better than none.

I don't know for a fact but I think that the probes on the Mallard used 12 volts and the newer Itasca's very low voltage much like an ohm meter, and the build up on the walls on the inside of the tanks would allow a small current to flow through that built up between the probs.

dougrainer wrote:
Tank sensors DO WORK. BUT, they fail because RV'ers do NOT follow normal procedures to keep the sensors/wall clean. LOTS of Rv'ers do not use Black tank chemical treatment. THAT causes Black tank issues. MORE THAN LOTS do NOT use Gray tank treatment. THAT causes Gray tank issues. Once the metal in the tank probes become coated and the sides of the tank become coated, they will then NOT work correctly. No amount of cleaning will restore or remove that caked on slime on the side of the tanks. The pressure wash usually will get rid of some of the wall slime. The system is simple. You have 4 or 5 probes. 1/3-2/3-full or 1/4-1/2-3/4-full with a single ground probe. When the liquid touches the probes this completes the circuit and turns on the appropriate light on the panel. I ALWAYS ask customers that complain, how come the FRESH system ALWAYS works? Because there is NO dirty water. I have LOTS of full timers that never have a problem because they spend the money and time to treat the 2 tanks from new. It always seems the complaints on these forums always come from newbies that buy used and the previous owners caused the problem. LAST, yes, external sending units like the See Level system is a good way to go to prevent false readings. Doug

Good post and info - do you have suggestions on products that work best?

Tank sensors DO WORK. BUT, they fail because RV'ers do NOT follow normal procedures to keep the sensors/wall clean. LOTS of Rv'ers do not use Black tank chemical treatment. THAT causes Black tank issues. MORE THAN LOTS do NOT use Gray tank treatment. THAT causes Gray tank issues. Once the metal in the tank probes become coated and the sides of the tank become coated, they will then NOT work correctly. No amount of cleaning will restore or remove that caked on slime on the side of the tanks. The pressure wash usually will get rid of some of the wall slime. The system is simple. You have 4 or 5 probes. 1/3-2/3-full or 1/4-1/2-3/4-full with a single ground probe. When the liquid touches the probes this completes the circuit and turns on the appropriate light on the panel. I ALWAYS ask customers that complain, how come the FRESH system ALWAYS works? Because there is NO dirty water. I have LOTS of full timers that never have a problem because they spend the money and time to treat the 2 tanks from new. It always seems the complaints on these forums always come from newbies that buy used and the previous owners caused the problem. LAST, yes, external sending units like the See Level system is a good way to go to prevent false readings. Doug

cavie wrote:
Forget you ever saw them. Non work forever. learn to keep track of your usage. You will sleep better.

X2I agree I have never had the sensors work though the 1st year on all the trailers I've owned and I've owned several.

In the fresh water tank(s) if the overflow has water running out .... it is full if you open the drain and nothing comes out it is empty.

Black water same thing but more visual, lol.

None worth your time or effort. Once you've done the RV thing for a few years you tend to ignore certain things that make you scream and this is one of them.

Forget you ever saw them. Non work forever. learn to keep track of your usage. You will sleep better.

Planecrazy05 wrote:
Hello everyone,

My wife and I have a fleetwood Bound 2010 35H and our black/gray sensors never show empty. Actually the black tank shows full and the gray flashes 2/3 to full even when the tanks are emptied

And they never will show empty unless you get very lucky.

The "Sensor" is basically a nail (Technically it is a metal rod) stuck in the side of the tank. if the side of the tank is "Slimed" then the nail is wet all the time and thus the sensor does not show empty.

There are several possible solutions

HORST miracle probes These are still "Nails" but they have some added features and are advertised as being immune to the problem above.

Pneumatic sensors (Pressure switches) I"m supposed to have some but I don't (long story) these work..... on pressure. they can also fail.

See-Level sensors. DO not have them but everyone I've spoken with who does says very nice things.. These work..... differently.


What can you do with the existing sensors
Cleaning the tank (Geo method) has worked for me so has "Blasting" the sensor wall with a home made version of the Valtera Master Blaster tank cleaning wand... But not often

Haveing the tank professionally steam cleaned would work but is expensive.

I'd suggest the See Level system or what most of us do. Live with it.

Planecrazy; I think there are a lot of good suggestions mentioned here to solve your problem but if you're like me and prefer to make the sensors work like they're supposed to you might try what I've been doing for years and 6 rvs. Since my gray water tank is totally inaccessible for flushing, I put about a quarter cup of tsp powder that has been dissolved in water and about the same amount of Calgon water softener powder into the gray water tank and then fill the rest of the tank with water, let it sit at least over night drain in the morning and you're good to go. The black water tank is usually accessible through the top of the bowl and that is where I put a water powered wand in and blast the bowl and the sensors. Keep in mind where the sensor are located and concentrate on water blasting that area. I've done this for over 25 years and it has always worked for me.