Been having issues with my gray/black sensors recently. Even after dumping it reports 1/3 full on black and 2/3 on gray. First I verified that it was draining properly - after emptying I put a bowl of dyed water down the gray, and then I drained it into the bowl and got back the same amount and it was dyed. After I empty I put Calgon/Blue Dawn in the holding tanks with 4-5 gallons of water. Yesterday I put all hot water in the gray tank with a generous amount of both before heading out on a 4 hour drive to try to let it swish around and clean the tank and sensors.Is there anything I can do to fix it? The unit is less than 3 months old.

After reading posts about this for years, I've concluded that almost nobody has working sensors.

superrayzor wrote:Been having issues with my gray/black sensors recently. Even after dumping it reports 1/3 full on black and 2/3 on gray. First I verified that it was draining properly - after emptying I put a bowl of dyed water down the gray, and then I drained it into the bowl and got back the same amount and it was dyed. After I empty I put Calgon/Blue Dawn in the holding tanks with 4-5 gallons of water. Yesterday I put all hot water in the gray tank with a generous amount of both before heading out on a 4 hour drive to try to let it swish around and clean the tank and sensors.Is there anything I can do to fix it? The unit is less than 3 months old.Did this help??Personally, instead of using a dishwashing soap that makes tons of suds, I use a laundry detergent (Oxy-Clean), that seems to do a better job. Each morning, prior to travel, I use the liquid Oxy-Clean and liquid Calgon along with about 5 gals of water and I never experience odors or faulty tank gauge sensors. On non-traveling days, and when dumping the black tank, I will use the soapy water from the gray tank to help flush out everything in the black tank.If you haven't headed out yet, let us know after you have completed your initial trip. You may have to do this several times if your tanks are really dirty.Be sure to ALWAYS use LOTS of water in daily usage and when draining.Good luckRon

superrayzor wrote:Been having issues with my gray/black sensors recently. Even after dumping it reports 1/3 full on black and 2/3 on gray. Is there anything I can do to fix it? The unit is less than 3 months old.This has nothing to do with the age of the trailer but rather the simplistic sensor probes which protrude into the tank and therefore clog quite easily. Many if not most of us who have been at this for awhile have decided we just don't care but for those that do the solution is to switch to a tank monitoring system using sensors that don't protrude through the tank wall. Walex recently introduced a tank cleaner called Commando that is designed to clear the probes ... I've used it myself and it does seem to clear a lot of additional crud out of the BW tank.

Yea I got used to my black tank sensor being wrong. Everyone once in while ill travel with my black tank half full of water and treatment to get rid of the smell and clean off the sensor. but by the end of the trip the sensor is messed up againI do take care of my fresh water tank and sensor though. Where I live we have pretty hard water so the tank/sensors can get build up and jam the inline filter

Common problem. Fairly difficult to keep the sensors clean as they require constant cleaning.

Gray/Black sensor problems | Good Sam Community

26 Replies

thestoloffs
Explorer
Jul 01, 2016
Garnet Industries See-Level RV tank monitors work on the outside of the tanks, so they're far less affected by tank buildup than the screw-type sensors.
superrayzor
Explorer
Jun 30, 2016
Padlin wrote:
If you want the sensors to work you have to install something better.

Like what?
Padlin
Explorer
Jun 29, 2016
If you want the sensors to work you have to install something better.
JohnG3
Explorer II
Jun 29, 2016
Stormy Eyes wrote:
JohnG3 wrote:
I've used the ice and water method several times with great to moderate success. For me that is the easiest and quickest way to mitigate the sensor issue. Just remember to use a lot of ice and at least 10-15 gallons of water and put it all in the tanks just before you hit the road. A straight road does little, the more up, downs and turns the better and you DO NOT have to drive like an idiot. Normal driving on a curvy road will work fine. Depending on the weather dump after an hour or so of starting the drive.

Certainly one can drop ice into the black tank via the toilet, but my problem is my non-contact grey sensor. How would one get a large amount of ice into the grey tank? Though I do not really think the grey tank walls are dirty, I am willing to experiment with various methods to clean/ maintain it.

I haven't used this idea but I saw where someone recommended a gallon of Simple Green and 10 gallons of water in the grey tank.
Stormy_Eyes
Explorer
Jun 28, 2016
Veebyes wrote:
JMO, but worrying about those sensors is a waste of valuable time. It does not take long to get to know hoow many nights you can go on a tank of water. Measure it in person/nights. My rough calculation is 10gal per person per night.

You will also get to know how many days to need to empty tanks. Those dopey guages can read whatever, you will have a pretty good idea.
.

I'll be using your method unless my grey sensor starts fuctioning again. I have measured how much grey DH and I generated in a week while using campground showers. In the future, I'll learn how much when using the RV shower. I should then be able to manage nicely without the gauge.
Stormy_Eyes
Explorer
Jun 28, 2016
SoundGuy wrote:
Stormy Eyes wrote:
Like so many others, I am having trouble with a sensor...grey tank in my case.

Recommended by a friend I started using Walex Elemonate in my grey tank last year and was surprised to find my GW sensor actually works! :B

Thanks for the recommendation. I am always willing to try a different product.
Stormy_Eyes
Explorer
Jun 28, 2016
JohnG3 wrote:
I've used the ice and water method several times with great to moderate success. For me that is the easiest and quickest way to mitigate the sensor issue. Just remember to use a lot of ice and at least 10-15 gallons of water and put it all in the tanks just before you hit the road. A straight road does little, the more up, downs and turns the better and you DO NOT have to drive like an idiot. Normal driving on a curvy road will work fine. Depending on the weather dump after an hour or so of starting the drive.

Certainly one can drop ice into the black tank via the toilet, but my problem is my non-contact grey sensor. How would one get a large amount of ice into the grey tank? Though I do not really think the grey tank walls are dirty, I am willing to experiment with various methods to clean/ maintain it.
Veebyes
Explorer II
Jun 28, 2016
JMO, but worrying about those sensors is a waste of valuable time. It does not take long to get to know hoow many nights you can go on a tank of water. Measure it in person/nights. My rough calculation is 10gal per person per night.

You will also get to know how many days to need to empty tanks. Those dopey guages can read whatever, you will have a pretty good idea.

Always add a few gallons of water to the black tank to slosh around on the way home or to the next CG. No need to make the tank surgically clean but you don't want stuff drying up in there either.

People get into trouble by hooking up to unlimited CG water without thinking of limited holding tank capacity. The camper drawing from his own freshwater tank is much more concious of his water use.
JohnG3
Explorer II
Jun 28, 2016
I've used the ice and water method several times with great to moderate success. For me that is the easiest and quickest way to mitigate the sensor issue. Just remember to use a lot of ice and at least 10-15 gallons of water and put it all in the tanks just before you hit the road. A straight road does little, the more up, downs and turns the better and you DO NOT have to drive like an idiot. Normal driving on a curvy road will work fine. Depending on the weather dump after an hour or so of starting the drive.
lanerd
Explorer II
Jun 28, 2016
Unfortunately, once there is a build up on the sensors and is left for a longer period of time before trying to clean it off, will be very difficult to remove. To keep the sensors working properly, regular (and often) cleaning is required from day one.

Both of my motor homes were perchased new and I have never had a problem with the tank sensors in either one. However, my TT was used (if even only briefly) but was allowed to set at the bank (repossessed) for about six months and naturally, the prior owner did not clean it out prior to it being hauled off.

It took me many cleanings (see my post above) to finally get the sensors to work but once they did, they worked just fine for as long as I had the trailer.

Ron