Black & Gray Water Level Gauges Wrong

[lexi210]

Our 2007 Lexington 210:

After draining both black and gray tanks the gauges still read as much as 1/2 to 3/4 full. The gauges do read full before dumping but never go below 1/2 to 3/4 full after draining.
What is the best cleaning process to get them to read correctly after draining?

[Mdaniels4]

Flush them if you have that connection. If I just dump them, my gages still say may 1/2 full. But a flush spray for about 15 minutes and all show empty.

[lexi210]

Originally Posted by Mdaniels4

Flush them if you have that connection. If I just dump them, my gages still say may 1/2 full. But a flush spray for about 15 minutes and all show empty.

Thanks, but how do I do a “Flush Spray”? Sorry but I’m new to this kind of maintenance.

[Mdaniels4]

Your trailer may or may not have it. It's a connection near the city water inlet. You keep the blank drain open, connect a separate hose, and there are sprayers inside the black tank.

[jimmoore13]

Something like this black tank cleaning wand might help.

It functions somewhat like the black tank flush mechanism described by others. This goes down the toilet (when the water supply to the RV is off), and it jets water onto the sides of the tank.
In many cases, it may be desirable to use the wand for a few minutes, give the water time to soften dried tissue and other solids, which may be obscuring your sensors, then spray again.

Assuming your sensors are just covered in crud, this should make them function normally, and it will also reduce crud buildup in the entire tank.

[T11ravis]

Good long flush always helps but...
I've had gauge issues with every RV I've owned. Some just don't seem to work right.

[Lilrebal2]

I had the same problem with my 2016 FR Wildwood. Like u I googled and went on these sites. What finally worked for me was Calgon water softener ( u find it in the fabric softener isle) and Dawn dish detergent (This helps break down any grease that might be built up) . I poured into both my gray and black tanks and let it sit then when we took the trailer camping It got sloshed around in the tanks so by the time we got to the campground after hooking up the sewer hose I emptied it. Oh wow the stuff that came out. I have a clear elbow on the end of my sewer hose that way you can see when it's clean. What happens is that tissue or other stuff might get on the sensors in your tanks. If u let it sit it will get hard and makes u have false readings. I try not to put tissue in my toilet. I use a small trash can and just take it daily while you camping. Sometimes u do have an emergency but just make sure u get the toilet paper recommended for RV"s. I also use a 2 ply regular one also. u just want to make sure it's one that will dissolve quickly. U also know to get the toilet treatment stuff that u pour in your tank after each dump. They also make a treatment to go in your grey tank also. I use it plus I use Dawn dish detergent anyways just because it does work well on grease. Hope this helps.

[kkelly]

I had the same problem with my 5th. I tried everything, then my plumber recommended a digester product used for septic systems. They come “alive” in water and gobble up everything. My rig is in winter storage so I can’t give you the product name. I worked like magic. I mix a scoop full in a bucket of water and pour it in the toilet and flush. Also I don’t dump until over 2/3 full, even if it means letting it sit for long periods of time. Oh, and never any smell.
Good luck.

[T11ravis]

Originally Posted by kkelly

I had the same problem with my 5th. I tried everything, then my plumber recommended a digester product used for septic systems. They come “alive” in water and gobble up everything. My rig is in winter storage so I can’t give you the product name. I worked like magic. I mix a scoop full in a bucket of water and pour it in the toilet and flush. Also I don’t dump until over 2/3 full, even if it means letting it sit for long periods of time. Oh, and never any smell.
Good luck.

This stuff?
RID-X® RV Toilet Treatment (Liquid)

[kkelly]

No, it is clearly for septic systems and available from plumbers or suppliers. It’s not cheap. But I’ve had mine for probably 8 yrs and still 1/2 full.

[kkelly]

Just to add to my last. Camping supply places may sell something similar now, I’ve just never looked.

[Larry Cole]

There are various ways to flush your tanks, as suggested by others on this forum. But I have learned that there are so many things that render the gauges useless that I stopped relying on them. Get used to the average amount of time it takes to fill your tanks and then dump them. Then you know your tanks are empty regardless of what the gauges say.

[LindaNTom]

If your toilet is right above your tank like mine I was able to dump a couple of 5 gallon buckets of water down the toilet and drain after each one .that fixed the problem for me.

[jtesta1]

They need to stop putting gauges on tanks. They never work and confuse the hell outta people. Just wait till your tanks get full then drain and flush them . Forget about the guages.

[santarich]

I am reading this thread with a lot of interest everyone!
Both my gray and black water levels always are wrong. The gray shows 1/3 full and the black shows 2/3 full. I had tried:
1. Ice cubes like 10 trays full with white vinegar and taking the RV for a BIG side to side ride going over bumps to try and knock/shake the problem loose
2. Vinegar and water only with a 50-50 mix
3. Filling 4 times as full as it could get and trying to wash the problem out
4. Buying the tank chemicals that promised to eat away the problem and didn't work
5. Adding Pine-Sol to the water at a 50-50 mix ( sure smelled clean...lol).

None of the above made any difference.

[SailorSam20500]

The sensors that come with most RV's are INSIDE of the tanks (at install, they poke a hole in the tank and put in the sensor). So "stuff" can accumulate on them and cause incorrect readings. Many people, once they realize the readings are wrong, just ignore them. SeeLevel and maybe other vendors provide a monitoring system that is entirely outside of the tanks and they claim they are more accurate. (I haven't used them) You can read an explanation here: RV Holding Tank Monitor System | ModMyRV

[andymil]

Check this thread.

http://www.forestriverforums.com/for...rs-144771.html

My black tank shows empty when empty and shows 1/3 full when I add 2 gallons to an empty tank.

OEM sensors are almost useless. The best you can hope for is if the "full" sensor lights when the tank is almost full

[Walholler]

For the best piece of mind with those tank gauges, just ignore them. When you hear the gurgling noise coming from the tanks as you shower or flushing the toilet, go dump your tanks. Tank gauges are installed by the manufacturer to drive the RV owner insane and to enrich themselves with selling spare sensors.

[MartiB]

I have the opposite problem. After nearly a week, though I'm the only one using the trailer, my gauges for black and gray water still show almost empty (1 light on the panel).