Gray Tank lights..

[GT4six]

Our Gray Tank indicator lights keep showing 2/3 full. I figured there might have been something stuck there but I kept on filling it up and emptying it....no dice. It keeps reporting 2/3 full even though I know is empty.

What do you do? has anyone experinece this?...black and fresh light are good but just the Gray.

Thank you all in advance!

[alparmer]

Something is causing the two sensors to have continuity. You could try filling it up 3/4 full and adding dish soap, bleach, etc. and take it for a ride. I've heard of folk even adding ice to help scrub the sludge.

[nosaint3]

Both my grey water lights read 2/3's full. I don't waste any more water trying to clean them until I travel. Then sometimes it works and sometimes it doesn't.

[rvpezzano]

Our 08 350ts tank sensors act up also. I put in a grey tank flusher in it. When I drilled the hole, I put my finger in the tank, and it was slimmy. We are full timers now, I put a cup of Dawn and a cup of Calgon. I did this in Washington state and by the time we got to AZ, it was working. It took a few treatments but I'm sure the flusher helped also. The black tank has it's own back flush but I use the wand down the toilet, that seems to do a more thorough job. I only use that method once every every few months. If you so inclined, you can see the black tank level through the toilet, at least on our model.
Have fun

[willingtonpaul]

i have always cleaned my tanks 3 times a year with the following method:

empty tanks (both black and grey)
put in two or three cups of bleach
put in two cups of laundry detergent (any brand, but i like powder over liquid)
put in two or three cups of calgon water softener

fill the tanks to half full

drive round for 30 minutes with alot of turns to slosh the mix around

dump tanks.

the bleach disinfects/deodorizes
the laundry detergent cleans
the water softener keeps the walls of the tanks slippery so nothing sticks

this method has served me well over the last 25 yrs; even on low end campers with cheap sensors i've never had them act up. preventative maintenance is the key.

try this treatment two or three times and see if your sensors come back to working properly.

[bend302]

My grey tank has shown 2/3 full most of the last 3 years. I leave the valve open while sitting for 3 months in Fla. and it still stays the same. I pretty well ignore it because it will show full when the tank fills during short term camping.

I have tried the Calgon (geo method) to no avail.

Bill

[rvpezzano]

The bleach doesn't bother the dump valves?

[alparmer]

Originally Posted by rvpezzano

The bleach doesn't bother the dump valves?

I always follow up with Camco Cocolube after using chemicals in the tank.

[willingtonpaul]

Never had a problem with bleach bothering the valves

[alparmer]

Originally Posted by willingtonpaul

Never had a problem with bleach bothering the valves

If you eat a lot of Mexican food, you will never have problems with the valves.

[Kuba]

Second year with black reading 2/3. I dont bother

Sent from my Lenovo P780 using Tapatalk

[GT4six]

OK - I guess that answers my question. However, I'm really surprised how common this glitch is and surprised FR hasn't added the flush feature like in the black tanks.

Thanks to all of you that contributed

Funny how you think you are the only with an issue until....

[bob7794]

When a film get on the sides of the tanks, it will close the circuit and give a positive reading to the lights. The type of sensors that come in the tanks look like slightly convex buttons on the inside of the tank. Cleaning will sometimes solve the problem, but only temporarily. I fixed mine permanently several years ago by replacing the probes with Horst Miracle Probes. These consist of a copper wire, that protrudes into the tank. The top part of the wire is hooded by plastic that shields the copper sensor. The difficulty of this task will be determined by the accessibility of your sensors. My tanks were exposed so the job was not too difficult. You can read about these probes here...Horst Miracle Probes for Wastewater Tanks in Recreational Vehicles RVs

[SemperFi3088]

My Black was doing that so I decided to to a flush, attaching the external water source to it. Fixed the problem