Tank Monitor Accuracy

[tgduffy]

My new TT has a 30 gallon grey, 30 gallon black, and a 40 gallon fresh tank. Just how accurate are the tank level indicators lights? I ask because when my grey reflects 1/3 full (10 gallons ish) and the black reflects 1/3 full (again about 10 gallons), my fresh will still show full or 2/3 full. I'm pretty good at math and if the grey + black levels are 20 gallons total, then why does my fresh still show somewhere between full and 2/3 when in reality it's probably half full.
I physically tested all this by filling up the grey and black tanks 10 gallons at a time. Those indicators are accurate. Maybe I just need to use the black and grey levels to determine what's left in my fresh? I'm under warranty but I don't really want to haul the trailer back to the dealer for one indicator light.
Suggestions?

[bikendan]

No such thing as accurate OEM tank monitors.
Except possibly the FW tank.

[tgduffy]

It's my fresh water that seems to be registering more water than what's really in the tank. My grey and black seems to be right on.

[wahoonc]

I look at them as a form of entertainment. They are marginal at best for actually measuring tank levels. I have had some that were off by over 30%, there are several factors that come into play, like did they really mount the sensors in the proper place, are they wired correctly, are the sensors fully functional? I have seen all of the above at some point or another. There are apparently two decent aftermarket systems on the market, SeeLevel and iSeries are the two that I am aware of.

Aaron

[fella10]

Originally Posted by tgduffy

It's my fresh water that seems to be registering more water than what's really in the tank. My grey and black seems to be right on.

none of the original monitors are calibrated, thus not very reliable, ...... we don't depend on any of them,...... we can look into the toilet to see how that level is doing,...... since we use the Sewer Solution, we leave the gray tank open to drain all the time,..... and the FW tank has read full since new and we've never put water in it,.......

[prairiecamper]

Originally Posted by bikendan

No such thing as accurate OEM tank monitors.
Except possibly the FW tank.

x2. LOL

[tgduffy]

We usually dry camp, no hookups. So any suggestions on monitoring the grey and black tanks. Taking a look into the toilet would seem like a way to determine "it's full!". Can't see much further down into the black tank from the toilet. or does it become just a trial and error and get feel like "I know I can basically go for 3 days with getting full".

[VinceU]

Sounds like wiring error or looseness. They normally work fine, no fouling or pollution to foul tank.

[Tireman9]

I agree with most others. Holding tank levels that RV company selects are not worth the wire used to power the lights. All kinds of items and chemicals are supposed to "clean" the gunk off the sensors but they don't work or don't work for long.

RV companies simply don't care enough about their customers to develop and install a system that works. RV companies IMO are only interested in installing the lowest cost (lowest quality) systems unless they involve "smoke & mirrors" that the sales man can mesmerize prospective customers with.

IMO salesmen don't even want to mention holding tanks or their maintenance in the fear that they might loose a sale.

If you pay attention and conserve a bit you will soon learn how many days you can go between dumps. Looking down into the black tank is OK on some RVs so that will tell when you have to dump. Wife & I can go 4 to 6 days but we use campground showers when the wife considers them clean enough to use. Otherwise 3 to 4 days.

[ShermanD]

Take a look underneath your RV some time at how the tank level indicators are set up, this will give you an idea of how they work, which is by resistance in the electrical circuitry. The 1/3 light will not go on until the water level reaches the electrical contact point and will remain at 1/3 until it reaches the 2/3 pickup electrical contact. It will then remain at 2/3 until it reaches the full pickup contact, at which point the tank is really about 3/4 full.

Therefore, you may be at half full and still be reading 1/3 full, you may be at 5/8 full and still be reading 1/3 while at the same time you may almost 1/3 full and still be reading empty.

The level indicators are nothing more than idiot lights that are provided for the sole purpose of giving you some idea that it is either time to think about emptying or filling depending on the tank. This is why you want to think about emptying if you have hit 2/3 full or filling after you reach 1/3 full.

[fella10]

Originally Posted by tgduffy

Taking a look into the toilet would seem like a way to determine "it's full!". Can't see much further down into the black tank from the toilet. .

you can see the level if you really want to,.... yes, you're looking into a dark hole, thru flowing water, so it requires a little effort,.... helps if the room is dark and using a flashlight, just like you would looking into any other dark hole,..... but doing that is much more reliable than the tank monitors,.... after awhile you will learn about how many days it takes for you/your family usage to near the full level,..... that's how we monitor our black tank,...... there are hundreds of post complaining about the tank monitors,....... we don't rely on them so we don't have any complaints about them, but that's just us,....

[SeaDog]

with regard to gray and black tanks as soon as any scum accumulates on the walls of the tanks the indicators will read wrong and no matter what you do may never read correctly. With me it has been a trail and error with three tanks I have never filled the black tank full

[raytwntrvlr]

Mine seem fairly accurate. I ran a check with a garden hose and an $8 water meter and found the lights to be within 5 gallons or so of what I expected. Go to Amazon and get your hands on one of those inexpensive hose end meters. Mine displayed 4.9 gallons after I filled a 5 gallon bucket... not bad.